Is ft/s faster than mph?

No—ft/s is a smaller unit, so the number is bigger for the same speed. 1 mph = 1.467 ft/s 100 ft/s = 68 mph (the ft/s number is bigger, but it's actually slower than "100 mph") Think of it like inches vs feet: 12 inches = 1 foot. "12" is bigger than "1", but they're the same length. Similarly, "100 ft/s" looks bigger than "68 mph", but they're the same speed.

What is the speed of sound in ft/s?

Approximately 1,125 ft/s at sea level, 68°F (767 mph, 343 m/s) = Mach 1 Temperature dependence : 32°F (0°C): 1,087 ft/s 68°F (20°C): 1,125 ft/s (standard reference) 86°F (30°C): 1,145 ft/s Practical rule : "Sound travels about 1,100 feet per second" Lightning distance trick : See lightning flash Count seconds until thunder: "one Mississippi, two Mississippi, three..." Multiply seconds by 1,100 feet Divide by 5,280 (feet per mile) to get miles Example: 5 seconds → 5,500 feet → ~1 mile away Why bullets are "supersonic" or "subsonic" : Supersonic (> 1,125 ft/s): Creates sonic boom/crack Subsonic (< 1,125 ft/s): No sonic crack (quieter with suppressor)

How do I convert mph to ft/s in my head?

Method 1 (rough) : Multiply by 1.5 60 mph × 1.5 = 90 ft/s (actual: 88, close!) 40 mph × 1.5 = 60 ft/s (actual: 58.7, pretty close) Method 2 (better) : Use the "22/15 rule" or remember key values 30 mph = 44 ft/s 60 mph = 88 ft/s 90 mph = 132 ft/s Scale from these: 45 mph = halfway between 30 and 60 → (44+88)/2 = 66 ft/s Method 3 (precise) : Multiply by 1.467 (or 22/15) 50 mph × 1.467 = 73.35 ft/s

Why do bullets use ft/s instead of mph?

Four main reasons : Historical : US firearms industry developed using FPS system (foot-pound-second) Practical scale : Bullet velocities (1,000-3,000 ft/s) fit well, whereas 700-2,000 mph sounds awkward Short-duration events : Bullets travel for fractions of a second, so "per second" is more intuitive than "per hour" Ballistic calculations : Easier math for drop (inches), time of flight (milliseconds), energy (foot-pounds) when velocity is in ft/s Example : .223 Rem bullet at 3,200 ft/s Distance in 0.1 seconds: 320 feet (easy mental math) If stated as 2,182 mph: distance in 0.1 sec requires mph × 1.467 × 0.1 = 320 feet (harder)

What is terminal velocity in ft/s?

Human skydiver : Belly-to-earth (stable, arms/legs spread): 176 ft/s (120 mph, 54 m/s) Head-down streamline (diving position): 295 ft/s (200 mph, 90 m/s) With parachute deployed : 15-25 ft/s (10-17 mph)—safe landing speed Other objects : Raindrop (small, 1mm): 20 ft/s Raindrop (large, 5mm): 30 ft/s Baseball : 146 ft/s (100 mph) Penny (myth-busting): 30-50 ft/s (not lethal!) Bowling ball : 335 ft/s (228 mph)—dangerous! Why terminal velocity varies : Air resistance balances weight. Bigger, heavier, or more streamlined = higher terminal velocity.

How fast is 300 ft/s in mph?

300 ft/s = 204.5 mph Formula : 300 ft/s × 0.682 = 204.5 mph Context : This is a common archery speed (compound bow arrow) or paintball velocity limit (280-300 ft/s) Comparison : 300 ft/s = subsonic (below 1,125 ft/s speed of sound) 300 ft/s = 91.4 m/s (metric) 300 ft/s = 199 knots (marine/aviation)

What does "subsonic ammo" mean?

Subsonic ammunition : Muzzle velocity < 1,125 ft/s (speed of sound) Why use subsonic : No sonic crack : Supersonic bullets create a sonic boom as they break the sound barrier—sounds like a loud "crack" Suppressor-friendly : With a suppressor (silencer), subsonic ammo is much quieter—only the muzzle blast is heard, not the sonic crack Hearing protection : Even without suppressor, subsonic is less loud Common subsonic rounds : .45 ACP : 850-900 ft/s (naturally subsonic, heavy bullet) 9mm subsonic : 950-1,050 ft/s (special loads, lighter powder charge) .22 LR subsonic : 1,050-1,100 ft/s Supersonic ammunition : Velocity > 1,125 ft/s Standard .223 Rem: 3,200 ft/s (almost 3× speed of sound!) Standard 9mm: 1,200 ft/s (just barely supersonic)

How far does a car travel in 1 second at 60 mph?

88 feet (exactly) Breakdown : 60 mph = 60 miles/hour 60 miles/hour × 5,280 feet/mile ÷ 3,600 seconds/hour = 88 feet/second Why this matters for safety : Reaction time : Average driver takes 1.5 seconds to react to hazard Distance during reaction : 1.5 seconds × 88 ft/s = 132 feet (before even touching brake!) Braking distance : Additional ~180 feet to stop (dry pavement) Total stopping distance : 132 + 180 = 312 feet at 60 mph Following distance "3-second rule" : At 60 mph, maintain 3 × 88 = 264 feet behind car ahead Gives 2× reaction distance (safer margin)

Can I use ft/s in scientific equations?

Yes, but you must use imperial units consistently: Kinetic energy (imperial) : KE (foot-pounds) = ½ × mass (slugs) × velocity² (ft/s)² 1 slug = 32.174 pounds-mass Or: KE (ft·lbf) = weight (lbf) × velocity² (ft/s)² / (2 × 32.2) Force (imperial) : F (pound-force) = mass (slugs) × acceleration (ft/s²) Or: F (lbf) = (weight in lbf / 32.2) × acceleration (ft/s²) For scientific work , SI units (m/s, kg, Newtons, Joules) are strongly preferred: No slugs vs pounds confusion International standards require SI Easier unit conversions (all decimal) Bottom line : You can use ft/s in calculations, but it's more complex than metric. For ballistics and US engineering where ft/s is standard, imperial equations exist. For research/publication, convert to m/s.

What's the difference between ft/s and ft/s²?

ft/s (feet per second) : Velocity—how fast you're moving ft/s² (feet per second squared) : Acceleration—how quickly your velocity changes Example (free fall) : Gravity acceleration : g = 32.2 ft/s² After 0 seconds: velocity = 0 ft/s After 1 second: velocity = 32.2 ft/s (acceleration added 32.2 ft/s) After 2 seconds: velocity = 64.4 ft/s (acceleration added another 32.2 ft/s) After 3 seconds: velocity = 96.6 ft/s Car example (0-60 mph in 5 seconds): Change in velocity: 60 mph = 88 ft/s Time: 5 seconds Average acceleration: 88 ft/s ÷ 5 seconds = 17.6 ft/s²

Where is km/h primarily used?

Kilometers per hour is the standard unit for road speed in most countries around the world that use the metric system—195+ countries representing approximately 95% of the global population. This includes all of Europe (except UK for roads), Asia (except Myanmar), South America, Africa, Australia, and Canada. Only the United States, United Kingdom (for road traffic), and Myanmar primarily use miles per hour (mph) instead.

While it uses SI units (kilometer and hour derived from second), the official SI unit for speed is meters per second (m/s). However, km/h is accepted for use with SI and is the standard for practical applications like road speed limits and weather reports. Scientists typically convert km/h to m/s for calculations (1 km/h = 0.278 m/s), but km/h remains universally understood and used globally for everyday speed measurements.

How do you convert km/h to mph?

To convert kilometers per hour to miles per hour, divide by 1.609 (or multiply by 0.621371 for more precision). Quick approximation: divide by 1.6. For example: 100 km/h ÷ 1.6 ≈ 62.5 mph (actual: 62.14 mph) 80 km/h ÷ 1.6 = 50 mph 120 km/h ÷ 1.6 = 75 mph For a rougher estimate, multiply km/h by 0.6: 100 km/h × 0.6 = 60 mph (close enough for casual conversation).

How do you convert km/h to m/s?

Divide the speed in km/h by 3.6 to get meters per second. Formula: m/s = km/h ÷ 3.6. For example: 100 km/h ÷ 3.6 = 27.78 m/s 90 km/h ÷ 3.6 = 25 m/s 36 km/h ÷ 3.6 = 10 m/s Why 3.6? Because 1 km = 1,000 meters and 1 hour = 3,600 seconds, so 1,000 ÷ 3,600 = 1 ÷ 3.6. To convert back from m/s to km/h, multiply by 3.6.

What is a good walking speed in km/h?

A typical comfortable walking speed is 5 km/h (about 3.1 mph), which translates to covering 1 kilometer in 12 minutes. Speeds vary by activity: Leisurely stroll: 3-4 km/h (window shopping, elderly pace) Average walk: 5 km/h (standard comfortable pace) Brisk walk: 6-7 km/h (fitness walking, power walking) Speed walking (race walking): 10-15 km/h (Olympic athletes reach 13-15 km/h) For reference, pedestrian crossing signals are typically designed assuming 4-5 km/h walking speed.

What is the typical highway speed in km/h?

Highway speed limits vary significantly by country, but 100-130 km/h (62-81 mph) is the most common range globally: 100 km/h: Canada, Australia, Japan (many highways) 110-120 km/h: Spain (120), Italy (130), France (130), Australia (110) 130 km/h: France, Austria, Belgium, Italy (motorways) 140 km/h: Poland, Bulgaria (motorway limits) Unlimited sections: Germany (Autobahn—advised 130 km/h, many sections unrestricted) Most drivers maintain 100-110 km/h as a comfortable highway cruising speed.

How fast is 100 km/h?

100 km/h is a common highway speed globally, equal to: 62.1 mph (about the speed limit on many US interstates) 27.8 meters per second (traveling the length of a basketball court every second) 1.67 kilometers per minute (1 km every 36 seconds) Reference points: 100 km/h = 100 meters traveled every 3.6 seconds At this speed, your reaction distance (before braking) is about 28 meters Total stopping distance on dry pavement: approximately 100 meters A commercial jet's cruising speed is about 9× faster (900 km/h)

What speed is considered fast for a car?

"Fast" depends on context, but general guidelines: On public roads: 80-100 km/h: Moderate highway cruising 120-140 km/h: Fast highway driving (legal limits in some European countries) 160+ km/h: Very fast (exceeds most legal limits worldwide, except unrestricted Autobahn) Vehicle performance: 200 km/h (124 mph): Sports car territory 250 km/h (155 mph): High-performance sports cars (often electronically limited) 300+ km/h (186+ mph): Supercars (Lamborghini, Ferrari, McLaren) 400+ km/h (250+ mph): Hypercars (Bugatti Chiron top speed: 490 km/h / 304 mph) For everyday driving, anything over 140 km/h is considered "fast" in most contexts.

Do planes use km/h or mph?

Professional aviation uses knots (nautical miles per hour) as the international standard for airspeed and navigation, not km/h or mph. However, speeds are often converted to km/h or mph for public understanding: Aviation standards: Airspeed, wind speed, groundspeed: Measured in knots Altitude: Measured in feet (even in metric countries) Distance: Measured in nautical miles For reference: 1 knot = 1.852 km/h (exactly) Typical commercial jet cruise: 450-480 knots = 830-890 km/h Fast business jet: 500+ knots = 925+ km/h Some small general aviation aircraft in Europe display airspeed in km/h, but this is uncommon professionally.

Why doesn't the whole world use km/h?

95% of the world does use km/h —only three countries primarily use mph: the United States, United Kingdom (roads only), and Myanmar. The reasons these countries retain mph include: United States: Infrastructure cost: Replacing millions of road signs would cost billions Cultural resistance: Strong attachment to traditional units ("metric conversion" politically unpopular) Dual system: US already uses metric extensively in science, medicine, military, but not road transport United Kingdom: Partial metrication: UK uses metric for most things (fuel sold in liters, food in grams) but retained mph for roads and distances Historical preservation: Miles deeply embedded in British culture and infrastructure Compromise approach: Speed limits in mph, but fuel economy measured in L/100 km creates confusion Myanmar: Considering metrication: Government has discussed switching to metric system including km/h Limited road infrastructure: Smaller road network makes conversion more feasible Historical note: Canada, Australia, and most former British colonies successfully converted from mph to km/h in the 1970s-1980s, proving large-scale conversion is achievable with political will.

How accurate are car speedometers in km/h?

Car speedometers are legally required to overestimate speed slightly to prevent drivers from accidentally speeding. Regulations vary by country: European Union (UN ECE R39 regulation): Speedometer must never underestimate speed Can overestimate by up to 10% + 4 km/h Example: True speed 100 km/h → speedometer shows 100-114 km/h (allowed range) Australia (ADR 18): Similar to EU: Never under-read, can over-read up to 10% + 4 km/h Typical real-world accuracy: Most modern cars: Overestimate by 2-5% at highway speeds 100 km/h indicated = 95-98 km/h actual speed (common) GPS speedometers: Generally more accurate (±1 km/h), but can lag during acceleration Why overestimate? Manufacturers err on the side of caution to avoid liability if speedometer under-reads and drivers get speeding tickets or cause accidents.

Why do planes and ships use knots instead of mph?

Historical Reason: Early aviation borrowed from maritime tradition. Pilots and sailors both navigate using latitude/longitude. Practical Reason: 1 knot = 1 minute of latitude per hour makes navigation calculations trivial. Using mph would require constant conversion (1 degree latitude ≈ 69 statute miles). Example: Knots: "Flying north at 60 knots for 1 hour = 1 degree north." mph: "Flying north at 69 mph for 1 hour = 1 degree north." (Awkward!)

Is saying "knots per hour" correct?

No! This is a common mistake. Wrong: "The ship is doing 20 knots per hour." Right: "The ship is doing 20 knots." Why? Knot already means "nautical miles per hour ." Saying "knots per hour" is like saying "miles per hour per hour" (which is acceleration, not speed).

How do I convert knots to mph mentally?

Quick Method: Add 15% Steps: Take the knot value (e.g., 40 knots). Calculate 10%: 40 × 0.1 = 4. Calculate 5% (half of 10%): 4 ÷ 2 = 2. Add them: 40 + 4 + 2 = 46 mph . (Actual: 46.03 mph—very close!)

What is the fastest speed ever recorded in knots?

Water Speed Record: 276 knots (317 mph) by Spirit of Australia (1978). Jet-powered hydroplane. Air Speed Record (Manned): 1,905 knots (2,193 mph, Mach 3.3) by SR-71 Blackbird. Wind Speed Record: 253 knots (291 mph) measured during Tropical Cyclone Olivia (1996) in Australia.

Do cars ever use knots?

No. Cars use: mph (miles per hour) in the US, UK. km/h (kilometers per hour) everywhere else. Knots are exclusively for maritime and aviation use.

Why is a nautical mile longer than a statute mile?

Statute Mile: Based on Roman measurements (1,000 paces = 5,280 feet). Arbitrary. Nautical Mile: Based on Earth's geometry (1 minute of latitude = 6,076 feet). Scientific. The nautical mile is 15% longer because it's tied to the planet's actual size.

How fast is the wind in a hurricane?

Hurricane Categories (Saffir-Simpson Scale): Category Wind Speed (Knots) Wind Speed (mph) Damage Tropical Storm 34-63 knots 39-73 mph Minimal Category 1 64-82 knots 74-95 mph Some damage Category 2 83-95 knots 96-110 mph Extensive damage Category 3 96-112 knots 111-129 mph Devastating Category 4 113-136 knots 130-156 mph Catastrophic Category 5 137+ knots 157+ mph Total destruction Threshold: A tropical storm becomes a hurricane at 64 knots (74 mph).

What is a "gale" in knots?

Beaufort Wind Scale: Force Name Wind Speed (Knots) Conditions 7 Near Gale 28-33 Difficult to walk 8 Gale 34-40 Twigs break off trees 9 Strong Gale 41-47 Roof damage 10 Storm 48-55 Trees uprooted 11 Violent Storm 56-63 Widespread damage 12 Hurricane 64+ Catastrophic Gale Warning: Issued when winds are expected to reach 34-47 knots .

How fast is Mach 1 in knots?

Mach 1 (speed of sound) varies with temperature and altitude. At Sea Level (59°F): Mach 1 ≈ 661 knots (761 mph, 1,225 km/h). At 35,000 feet (typical cruise altitude): Mach 1 ≈ 573 knots (659 mph, 1,062 km/h). Concorde Cruise Speed: Mach 2.0 ≈ 1,150 knots (1,323 mph).

What is a sonic boom?

When an object travels faster than sound (Mach 1+), it creates pressure waves faster than they can propagate away. These waves pile up, forming a shock wave —a cone of intense pressure that trails the object like the wake of a boat. The "Boom": When this cone passes over you, you hear a sharp double "boom-boom" First boom: nose shock wave Second boom: tail shock wave Sounds like thunder or an explosion Can rattle windows, set off car alarms Damage Potential: Low-altitude supersonic flight: Can break windows, damage structures High-altitude supersonic flight: Boom reaches ground weakened, sounds like distant thunder Concorde cruised at 60,000 feet to minimize ground impact Continuous: The sonic boom is continuous along the entire flight path, not just when "breaking" the barrier. Everyone below the flight path hears a boom as the cone passes over them.

Why did the Concorde stop flying?

Economic and Regulatory Challenges: 1. Sonic Boom Restrictions: Banned from supersonic flight over most land masses Limited to oceanic routes (transatlantic primarily) Reduced potential markets dramatically 2. Fuel Consumption: Burned 3x more fuel than subsonic jets per passenger 17 tons per hour at Mach 2 cruise Rising fuel costs made operation increasingly expensive 3. Limited Capacity: Only 92-120 passengers (vs 400+ on Boeing 747) Small market for ultra-premium tickets Round-trip London-New York: $12,000+ (1990s-2000s) 4. Maintenance Costs: Complex systems required extensive maintenance Only two operators (British Airways, Air France) No economies of scale 5. Air France Flight 4590 Crash (2000): Metal debris on runway punctured tire Debris hit fuel tank, caused fire 113 killed Led to temporary grounding, increased insurance costs Public confidence damaged Final Flight: October 24, 2003 (British Airways) Modern Revival Attempts: Companies like Boom Supersonic developing new supersonic airliners with quieter "boom" and better fuel efficiency. Target: 2029-2030 service entry.

Can a car go Mach 1 on land?

Yes—but only one has officially done it. ThrustSSC (1997): Speed: 763 mph (Mach 1.016) on October 15, 1997 Location: Black Rock Desert, Nevada Driver: Andy Green (Royal Air Force fighter pilot) Power: Two Rolls-Royce Spey jet engines (from Phantom fighter jets) Thrust: 110,000 lb (50,000 kg) Weight: 10.5 tons First land vehicle to create sonic boom Challenges: Extreme instability at transonic speeds Required perfect desert surface (dry lake bed) Aerodynamic design critical (shaped like a fighter jet) Braking from 760 mph without flipping Bloodhound LSR (In Progress): Target: 1,000 mph (Mach 1.3) Hybrid jet + rocket propulsion Same driver (Andy Green) Testing ongoing in South Africa

What is "Critical Mach Number"?

Critical Mach Number (Mcrit) is the speed at which airflow over any part of the aircraft first reaches Mach 1—even if the aircraft itself is flying slower than Mach 1. Why This Happens: Air accelerates as it flows over the curved upper surface of wings Example: Aircraft flying at Mach 0.80, but airflow over wing reaches Mach 1.0 Consequences of Exceeding Mcrit: Shock waves form on wing surface Airflow separation behind shock waves Loss of lift (buffeting, "Mach tuck") Increased drag (transonic drag rise) Control problems Typical Values: Straight wing aircraft: Mcrit ≈ 0.75-0.85 Swept wing aircraft: Mcrit ≈ 0.85-0.92 Supersonic fighters: Mcrit > 0.95 Maximum Mach Number (MMO): Regulatory limit for aircraft (e.g., MMO = 0.90 for Boeing 737) Pilots must not exceed this speed

How do pilots calculate Mach number?

Instrumentation: 1. Machmeter (Cockpit Instrument): Combines pitot-static pressure measurements with temperature Directly displays Mach number Standard on all jet aircraft 2. Flight Management System (FMS): Computer calculates Mach number continuously Uses air data sensors (pitot tubes, static ports, temperature probes) Displays on primary flight display Manual Calculation: $$ M = \frac{TAS}{LSS} $$ Where: TAS = True Airspeed (from airspeed indicator + altitude + temperature correction) LSS = Local Speed of Sound = 38.94 × √T (where T is temperature in Kelvin) Example: Altitude: 35,000 feet Temperature: -57°C = 216 K TAS: 487 knots LSS: 38.94 × √216 = 38.94 × 14.7 = 573 knots Mach: 487 ÷ 573 = Mach 0.85

Is Mach 10 possible for aircraft?

Yes—but extremely challenging. Achieved (Unmanned): NASA X-43A (2004): Mach 9.6 (7,000 mph) for 10 seconds Scramjet (supersonic combustion ramjet) technology Hydrogen fuel Launched from B-52 bomber + rocket booster Unmanned test vehicle Challenges at Mach 10: 1. Extreme Heat: Air friction generates 3,000°F+ surface temperatures Requires exotic materials (carbon-carbon composites, ceramics) Active cooling systems needed 2. Engine Technology: Turbojets don't work above ~Mach 3 (air too fast for compressor) Ramjets work Mach 3-6 (no moving parts) Scramjets needed above Mach 6 (air stays supersonic through engine) Very low thrust-to-weight ratio 3. Control: Hypersonic flight extremely unstable Milliseconds to react Requires autonomous flight control systems Current Applications: Hypersonic missiles: Russia (Kinzhal, Avangard), China (DF-ZF), US (under development) Space access: Potential for single-stage-to-orbit vehicles Research: NASA X-51 Waverider (Mach 5.1 sustained, 2013)

What is the fastest Mach number ever achieved?

By Manned Aircraft: SR-71 Blackbird: Mach 3.3 (2,193 mph) sustained cruise X-15 rocket plane: Mach 6.72 (4,520 mph) in 1967—still holds record By Unmanned Aircraft: NASA X-43A: Mach 9.6 (7,000 mph) in 2004 By Spacecraft: Space Shuttle re-entry: Mach 25 (17,500 mph) Apollo 10 (1969): Mach 36 (24,791 mph)—fastest manned vehicle ever Parker Solar Probe: Mach 550+ (430,000 mph relative to Sun)—fastest human-made object By Natural Objects: Meteors: Mach 50-200+ entering atmosphere

Why do some fighter jets have "supercruise"?

Supercruise is the ability to fly supersonic (Mach 1+) without using afterburners. Traditional Supersonic Flight: Requires afterburner (raw fuel sprayed into exhaust, ignited) Increases thrust 40-70% Burns 3-5x more fuel Can only sustain for minutes Supercruise Advantages: Fuel efficiency: Supersonic cruise without afterburner Extended supersonic duration: Hours instead of minutes Lower heat signature: Harder to detect with infrared missiles Greater range: Less refueling needed Aircraft with Supercruise: F-22 Raptor: Mach 1.8 supercruise Eurofighter Typhoon: Mach 1.5 supercruise Dassault Rafale: Mach 1.4 supercruise Concorde: Mach 2.04 supercruise (civilian application) How It's Achieved: Extremely efficient engines (high bypass turbofans with afterburner) Aerodynamic design minimizing supersonic drag High thrust-to-weight ratio

How loud is a sonic boom?

Loudness varies by altitude and aircraft size: Concorde: At 60,000 feet cruise: 100-110 decibels on ground (sounds like distant thunder) At 40,000 feet: 120+ decibels (can break windows) Fighter Jet: Low-altitude supersonic pass: 130-140 decibels (painfully loud, like artillery) High-altitude: 90-100 decibels (loud but not painful) Comparison: Normal conversation: 60 dB Lawn mower: 90 dB Rock concert: 110 dB Jet engine (close): 140 dB Gunshot: 160 dB Perceived Impact: Overpressure: 1-2 pounds per square foot (psf) typical for Concorde at cruise altitude 5+ psf: Can break windows 10+ psf: Structural damage to buildings Why Banned Over Land: Continuous disturbance along entire flight path Affects thousands of people per flight Disrupts wildlife Property damage lawsuits

Can shock waves be photographed?

Yes—through schlieren photography. Technique: Uses light refraction to visualize air density gradients Invented by August Toepler (1864), refined by Ernst Mach (1887) Shock waves create sharp density changes = visible patterns Modern Applications: Wind tunnel testing: Visualizing airflow over models Ballistics research: Photographing bullets in flight NASA testing: X-59 "quiet supersonic" aircraft development Airshows: Ground-based cameras capturing fighter jets' shock waves Iconic Images: Ernst Mach's 1888 bullet shock wave photographs NASA's T-38 shock wave interaction photos Schlieren video of sonic booms passing over landscape Smartphone Era: High-speed smartphone cameras can sometimes capture shock wave patterns from fighter jets with proper lighting conditions

Why do we use m/s instead of km/h in physics?

SI coherence : The meter per second is a coherent SI unit , meaning it combines base SI units (meter, second) without numerical conversion factors. This makes physics equations work directly: Force: F = ma where m is kg, a is m/s² → F is Newtons (kg·m/s²) Energy: KE = ½mv² where m is kg, v is m/s → KE is Joules (kg·m²/s²) Momentum: p = mv where m is kg, v is m/s → p is kg·m/s If you used km/h, you'd need conversion factors in every equation: 100 km/h = 27.78 m/s KE = ½ × 1000 kg × (100 km/h)² requires converting km/h to m/s first Using m/s keeps math simple and consistent across all physics

How fast is 1 m/s in everyday terms?

1 m/s ≈ slow walking pace Imagine taking one large step (about 1 meter) every second. That's 1 m/s. Equivalents : 1 m/s = 3.6 km/h = 2.2 mph Slower than average walking (1.4 m/s = 5 km/h) About the pace of a leisurely stroll Visual : If you're walking naturally and counting "one Mississippi, two Mississippi," you're covering about 1.4 meters per "Mississippi" (1.4 m/s).

What is the speed of light in m/s?

Exactly 299,792,458 m/s in vacuum (by definition) This number is exact because the meter is actually defined based on the speed of light: 1 meter = distance light travels in 1/299,792,458 of a second Since 1983, the meter has been defined this way Rounded for calculations : c ≈ 3 × 10⁸ m/s (300 million m/s) In different materials : Air: ~299,700,000 m/s (99.97% of vacuum speed) Water: ~225,000,000 m/s (75% of vacuum speed) Glass: ~200,000,000 m/s (67% of vacuum speed)

How do I convert m/s to knots?

Formula : knots = m/s × 1.94384 Step-by-step example (20 m/s to knots): 20 m/s × 1.94384 = 38.9 knots Or rough estimate: 20 × 2 = 40 knots Quick approximation : Multiply by ~2 (actual: 1.944) Common conversions : 10 m/s = 19.4 knots 15 m/s = 29.2 knots 20 m/s = 38.9 knots (strong wind) 25 m/s = 48.6 knots (gale force) 30 m/s = 58.3 knots (storm force) Why knots : One knot = one nautical mile per hour, where 1 nautical mile = 1,852 meters (approximately one minute of latitude). m/s to knots converter →

Is m/s the same as "mps"?

Yes, informally , but m/s is the correct SI symbol . Accepted notations : m/s (official SI symbol, most common) m·s⁻¹ (alternative SI notation using negative exponents) m s⁻¹ (with space, less common) mps (informal abbreviation, spoken English, not official) Never use : m/sec (mix of abbreviations) mps with periods (m.p.s.) MPS (capital letters change meaning) In scientific writing : Always use m/s or m·s⁻¹ In speech : "meters per second" or informally "m-p-s" (spelling out letters)

How fast is the speed of sound in m/s?

343 m/s at 20°C (68°F) at sea level Temperature dependence : Speed of sound increases with temperature 0°C (32°F): 331 m/s 15°C (59°F): 340 m/s 20°C (68°F): 343 m/s 25°C (77°F): 346 m/s Formula: v ≈ 331 + 0.6T (where T is temperature in °C) Altitude effects : Sea level: ~343 m/s 10,000 m altitude (jet cruise): ~299 m/s (colder air) Stratosphere: varies widely with temperature inversions Other materials (much faster in solids/liquids): Water (20°C): 1,481 m/s (4.3× faster than air) Steel: 5,960 m/s (17× faster than air) Diamond: 12,000 m/s (35× faster than air) Mach number : Mach 1 = speed of sound in that medium at that temperature

How do you calculate average velocity?

Formula : v_avg = Δx / Δt (displacement / time) Where : Δx = change in position (meters) Δt = change in time (seconds) Result in m/s Example 1 (straight line): Start: 0 m, End: 100 m, Time: 10 s v_avg = (100 - 0) / 10 = 10 m/s Example 2 (round trip): Start: 0 m, travel to 100 m and back to 0 m, Time: 20 s v_avg = (0 - 0) / 20 = 0 m/s (displacement is zero!) Average speed = 200 m / 20 s = 10 m/s (speed uses total distance, not displacement)

What velocity do you need to reach orbit?

Low Earth Orbit (LEO) : ~7,660 m/s (27,600 km/h, 17,150 mph) Why so fast : At this speed, centrifugal force balances gravity You're constantly falling toward Earth but moving sideways fast enough to keep missing it Orbit is continuous free fall Velocity by altitude : ISS altitude (400 km) : 7,660 m/s Geostationary orbit (35,786 km) : 3,070 m/s (slower because higher orbit) Moon's orbit : 1,022 m/s (around Earth at 384,400 km distance) Escape velocity (leave Earth entirely): 11,200 m/s (40,320 km/h) Challenge : Rockets must accelerate from 0 to 7,660 m/s while fighting gravity and air resistance—requires enormous energy.

How does wind speed in m/s relate to storm categories?

Beaufort Scale (wind force scale): Calm : 0-0.5 m/s Light air : 0.5-1.5 m/s Light breeze : 1.5-3.3 m/s Gentle breeze : 3.3-5.5 m/s Moderate breeze : 5.5-8.0 m/s Fresh breeze : 8.0-10.8 m/s Strong breeze : 10.8-13.9 m/s Near gale : 13.9-17.2 m/s Gale : 17.2-20.8 m/s Strong gale : 20.8-24.5 m/s Storm : 24.5-28.5 m/s Violent storm : 28.5-32.7 m/s Hurricane : >32.7 m/s (>118 km/h, >73 mph) Saffir-Simpson Hurricane Scale : Category 1 : 33-42 m/s (119-153 km/h, 74-95 mph) Category 2 : 43-49 m/s (154-177 km/h, 96-110 mph) Category 3 : 50-58 m/s (178-208 km/h, 111-129 mph)—major hurricane Category 4 : 58-70 m/s (209-251 km/h, 130-156 mph) Category 5 : >70 m/s (>252 km/h, >157 mph)—catastrophic

Can anything travel faster than light?

No physical object can reach or exceed the speed of light (c = 299,792,458 m/s) in vacuum. Why (simplified) : As velocity approaches c, relativistic mass increases toward infinity Would require infinite energy to accelerate to exactly c Only massless particles (photons) travel at exactly c Things that can "appear" to go faster : Phase velocity (wave pattern speed): Can exceed c, but carries no information Shadow/spot motion : If you sweep a laser across the Moon, the spot can move faster than c (but it's not a physical object moving) Expansion of space : Distant galaxies recede faster than c due to space expansion, not their motion through space Fastest things (relative to us): Photons: c (exactly) Neutrinos: ~c (very slightly slower, have tiny mass) Fastest spacecraft (Parker Solar Probe): 163,000 m/s = 0.05% of c

Speed Unit Converter

Convert between different units of speed or velocity

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About Speed Conversions

Convert between different units of speed or velocity

Convert between 7 different speed units including Meter per second, Kilometer per hour, Mile per hour, Foot per second, Knot, and more. Our free online converter provides instant, accurate conversions with formulas, examples, and conversion tables.

Quick Start: Speed Conversions

Convert between 15+ speed units instantly. Perfect for driving, travel, aviation, maritime navigation, and physics calculations.

Most Popular Conversions:

MPH to KM/H - US to international speeds
KM/H to MPH - Speed limit conversions
M/S to MPH - Physics to practical
Knots to MPH - Maritime & aviation
M/S to KM/H - Science to driving

Understanding Speed Conversions

Speed measures how quickly an object changes position—the distance traveled per unit of time. Essential for driving, travel planning, sports analysis, aviation, maritime navigation, and physics.

Why Speed Conversion Matters

International Driving & Travel: US speed limits use MPH; most of the world uses KM/H. Rental cars abroad require understanding local speed signs to avoid tickets.

Aviation & Maritime: Aircraft and ships use knots (nautical miles per hour). Understanding conversions to MPH or KM/H helps passengers grasp travel speeds.

Sports & Athletics: Sprint speeds use meters per second (m/s). Comparing to everyday speeds (MPH/KM/H) provides context for athletic performance.

Physics & Science: Scientific calculations use meters per second (SI standard). Converting to practical units (MPH/KM/H) makes results relatable.

Automotive & Performance: Car specs list acceleration and top speeds. International comparisons require conversions between MPH and KM/H.

Common Speed Units Explained

Metric System (International)

Meter per Second (m/s) - Base SI Unit: The fundamental speed unit in science. One meter traveled per second. Used in physics, engineering, and scientific calculations.

Kilometer per Hour (km/h or kph): Standard for road speeds globally. One kilometer traveled per hour. Used on speed limits, car speedometers, and travel times worldwide (except US/UK).

Imperial / US Customary

Mile per Hour (mph): Standard for road speeds in US, UK (partially), and few other countries. One statute mile traveled per hour. Used on speed limits and vehicle speedometers in the US.

Foot per Second (ft/s or fps): Used in ballistics, engineering, and some physics applications. One foot traveled per second. Common in American engineering contexts.

Specialized Units

Knot (kn or kt): One nautical mile per hour (1.852 km/h). Standard unit for maritime and aviation speeds worldwide. Named for historical "log line" knots used for measuring ship speed.

Mach Number (M or Ma): Ratio of object's speed to the speed of sound in the surrounding medium. Mach 1 = speed of sound (~343 m/s at sea level). Used for high-speed aircraft and spacecraft.

Speed of Light (c): Fundamental physical constant: 299,792,458 m/s (exact). Used in relativity and as reference for extremely high speeds.

Conversion Quick Reference

Common Conversions

From	To	Multiply By	Example
MPH	KM/H	1.60934	60 mph = 96.6 km/h
KM/H	MPH	0.621371	100 km/h = 62.1 mph
M/S	MPH	2.23694	10 m/s = 22.4 mph
M/S	KM/H	3.6	10 m/s = 36 km/h
Knots	MPH	1.15078	100 kt = 115.1 mph
Knots	KM/H	1.852	100 kt = 185.2 km/h

Metric Conversions

From	To	Multiply By
M/S	KM/H	3.6
KM/H	M/S	0.277778

Imperial Conversions

From	To	Multiply By
MPH	FT/S	1.46667
FT/S	MPH	0.681818

Practical Speed Examples

Road Speeds & Driving

Speed Limits (US):

School zone: 15-25 mph (24-40 km/h)
Residential: 25-35 mph (40-56 km/h)
Urban arterial: 35-45 mph (56-72 km/h)
Highway: 55-65 mph (89-105 km/h)
Interstate: 65-80 mph (105-129 km/h)
Rural interstate (TX): 80-85 mph (129-137 km/h)

Speed Limits (International):

Urban (Europe): 50 km/h (31 mph)
Rural (Europe): 90-100 km/h (56-62 mph)
Motorway (Europe): 120-130 km/h (75-81 mph)
Autobahn (Germany): No limit zones / 130 km/h advisory
UK motorway: 70 mph (113 km/h)

Vehicle Performance:

0-60 mph acceleration: Performance metric (0-97 km/h)
Supercar top speed: 200+ mph (322+ km/h)
Sports car: 150-180 mph (241-290 km/h)
Average sedan: 110-130 mph (177-209 km/h)
Economy car: 90-110 mph (145-177 km/h)

Aviation

Aircraft Speeds:

Cessna 172 (small plane): 122 knots (140 mph / 226 km/h)
Regional jet: 350-450 knots (403-518 mph / 648-833 km/h)
Boeing 737 cruise: 450-480 knots (518-552 mph / 833-889 km/h)
Boeing 787 cruise: 490-510 knots (564-587 mph / 907-945 km/h)
Concorde cruise: Mach 2.02 (1,354 mph / 2,179 km/h)
Fighter jet: Mach 1.5-2.5 (1,150-1,900 mph / 1,850-3,060 km/h)

Speed Terminology:

IAS (Indicated Airspeed): What instruments show
TAS (True Airspeed): Actual speed through air
Ground speed: Speed relative to ground (affected by wind)

Maritime

Ship Speeds:

Cargo ship: 12-15 knots (14-17 mph / 22-28 km/h)
Container ship: 20-25 knots (23-29 mph / 37-46 km/h)
Cruise ship: 20-24 knots (23-28 mph / 37-44 km/h)
Fast ferry: 35-50 knots (40-58 mph / 65-93 km/h)
Naval destroyer: 30+ knots (35+ mph / 56+ km/h)
Racing yacht: 15-25 knots (17-29 mph / 28-46 km/h)
Speedboat: 40-60 knots (46-69 mph / 74-111 km/h)

Water Speed Records:

World water speed record: 318 mph (511 km/h / 276 knots)

Sports & Athletics

Running Speeds:

Walking: 3-4 mph (4.8-6.4 km/h / 1.3-1.8 m/s)
Jogging: 5-6 mph (8-9.7 km/h / 2.2-2.7 m/s)
Running: 7-9 mph (11-14 km/h / 3.1-4 m/s)
Sprinting (average): 12-15 mph (19-24 km/h / 5.4-6.7 m/s)
Usain Bolt (peak): 27.8 mph (44.7 km/h / 12.4 m/s)
Marathon pace: 6-7 mph (9.7-11 km/h / 2.7-3.1 m/s)

Cycling:

Casual: 10-12 mph (16-19 km/h)
Commuting: 12-16 mph (19-26 km/h)
Road cycling: 15-18 mph (24-29 km/h)
Racing: 25-28 mph (40-45 km/h)
Sprint: 30-40 mph (48-64 km/h)
Velodrome record: 56 mph (90 km/h)

Other Sports:

Baseball pitch (fastball): 90-100 mph (145-161 km/h)
Tennis serve: 120-140 mph (193-225 km/h)
Golf drive: 150-180 mph (241-290 km/h)
Downhill skiing: 80-90 mph (129-145 km/h)
Speed skating: 30-35 mph (48-56 km/h)

Nature & Animals

Animals:

Cheetah: 70 mph (113 km/h) - fastest land animal
Pronghorn antelope: 55 mph (89 km/h)
Lion: 50 mph (80 km/h)
Greyhound: 45 mph (72 km/h)
Racehorse: 40-45 mph (64-72 km/h)
Elephant: 25 mph (40 km/h)
Human (Usain Bolt): 27.8 mph (44.7 km/h)

Wind Speeds:

Calm: <1 mph (<1.6 km/h)
Light breeze: 4-7 mph (6-11 km/h)
Moderate wind: 13-18 mph (21-29 km/h)
Gale: 39-46 mph (63-74 km/h)
Hurricane (Category 1): 74-95 mph (119-153 km/h)
Hurricane (Category 5): 157+ mph (252+ km/h)
Tornado (EF5): 200+ mph (322+ km/h)

Physics & Sound

Speed of Sound (Mach 1):

At sea level (20°C): 343 m/s (767 mph / 1,235 km/h)
At 10,000m altitude (-50°C): 299 m/s (669 mph / 1,077 km/h)
Varies with temperature and medium

Speed of Light:

In vacuum (c): 299,792,458 m/s (exact)
≈ 670,616,629 mph
≈ 1,079,252,849 km/h

Common Conversion Mistakes

Mistake 1: Wrong MPH-KM/H Conversion Factor

Error: "1 mph = 2 km/h" Correction: 1 mph = 1.609 km/h (not 2). Using 2 adds 25% error. For quick estimates, 1.6 is better.

Mistake 2: Confusing Statute Miles and Nautical Miles

Error: "1 knot = 1 mph" Correction: 1 knot = 1.151 mph. Nautical miles (6,076 ft) are 15% longer than statute miles (5,280 ft).

Mistake 3: Mixing Speed Units in Calculations

Error: Calculating time as "distance (km) ÷ speed (mph)" Correction: Units must match! Convert to same system first: km ÷ km/h OR miles ÷ mph.

Mistake 4: Confusing M/S with MPH

Error: "The car goes 30 m/s, so about 30 mph" Correction: 30 m/s = 67 mph (multiply by 2.237). M/s is much faster than mph—about 2.2× faster.

Mistake 5: Assuming Speed = Velocity

Error: "The car's velocity is 60 mph" Correction: Speed is scalar (magnitude only). Velocity needs direction: "60 mph north" is velocity. In casual use, often interchangeable.

Mistake 6: Wrong Mach Number Assumptions

Error: "Mach 1 = 767 mph everywhere" Correction: Speed of sound varies with temperature/altitude. Mach 1 at sea level ≈ 767 mph, but at 35,000 ft ≈ 660 mph.

Frequently Asked Questions

How many kilometers per hour are in a mile per hour?

There are approximately 1.60934 kilometers per hour in 1 mile per hour.

Formula: km/h = mph × 1.60934

Examples:

30 mph = 48.3 km/h (residential speed)
60 mph = 96.6 km/h (highway speed)
70 mph = 112.7 km/h (UK motorway limit)
100 mph = 160.9 km/h

Quick mental math: Multiply mph by 1.6 for estimates

60 mph × 1.6 = 96 km/h (actual: 96.6)

Reverse: 1 km/h = 0.621 mph

Convert MPH to KM/H →

How do I convert kilometers per hour to miles per hour?

Formula: mph = km/h × 0.621371 (or divide by 1.609)

Examples:

50 km/h = 31.1 mph (urban speed limit)
100 km/h = 62.1 mph (common highway speed)
130 km/h = 80.8 mph (European motorway)
200 km/h = 124.3 mph (high-speed train)

Quick mental math: Divide km/h by 1.6 or multiply by 0.6

100 km/h ÷ 1.6 ≈ 62.5 mph (actual: 62.1)

Memory aid: "100 km/h is about 60 mph"

Convert KM/H to MPH →

What is a knot equivalent to in mph?

One knot equals approximately 1.15078 miles per hour.

Formula: mph = knots × 1.15078

Examples:

100 knots = 115.1 mph (typical small plane)
200 knots = 230.2 mph (regional jet)
500 knots = 575.4 mph (airliner cruise)
10 knots = 11.5 mph (sailboat speed)

Why "knot"? Historically, sailors measured speed by counting knots on a rope trailing behind the ship over a fixed time.

Knots to KM/H: 1 knot = 1.852 km/h (exactly)

Convert Knots to MPH →

How do I convert meters per second to miles per hour?

Formula: mph = m/s × 2.23694

Examples:

10 m/s = 22.4 mph (brisk jog)
20 m/s = 44.7 mph (Usain Bolt sprint)
30 m/s = 67.1 mph (highway speed)
100 m/s = 223.7 mph (race car)

Quick mental math: Multiply m/s by 2.2

30 m/s × 2.2 = 66 mph (actual: 67.1)

Why this conversion? Physics uses m/s (SI unit), but everyday speeds use mph (US) or km/h (international).

M/S to KM/H: Multiply by 3.6 (easier conversion)

10 m/s × 3.6 = 36 km/h

Convert M/S to MPH →

How fast is Mach 1?

Mach 1 = Speed of sound, which varies with temperature and altitude.

At sea level (20°C / 68°F):

343 meters per second
1,235 kilometers per hour
767 miles per hour

At typical airliner cruising altitude (35,000 ft, -57°C):

295 m/s
1,062 km/h
660 mph

Why it varies: Sound travels faster in warmer air and slower in colder air.

Mach number examples:

Subsonic: <Mach 0.8 (most airliners)
Transonic: Mach 0.8-1.2
Supersonic: Mach 1.2-5 (Concorde: Mach 2.02)
Hypersonic: Mach 5+ (spacecraft re-entry)

Breaking the sound barrier: First done by Chuck Yeager in 1947 (Bell X-1).

What's the difference between speed and velocity?

Speed (Scalar):

Magnitude only—how fast
No direction specified
Example: "60 mph"
Always positive

Velocity (Vector):

Magnitude AND direction
Example: "60 mph north"
Can be positive or negative
Change in velocity = acceleration

Practical difference:

Car speedometer shows speed, not velocity
GPS shows speed (magnitude) but tracks direction separately
In physics problems, direction matters for velocity

Average velocity vs average speed:

Speed: Total distance ÷ time
Velocity: Displacement ÷ time (can be zero if you return to start)

How do I convert feet per second to miles per hour?

Formula: mph = ft/s × 0.681818

Examples:

10 ft/s = 6.8 mph (brisk walk)
50 ft/s = 34.1 mph (residential driving)
88 ft/s = 60 mph (highway speed)
100 ft/s = 68.2 mph

Quick mental math: Divide ft/s by 1.47 (or multiply by 0.68)

Useful fact: 60 mph = 88 ft/s (exactly)

Easy to remember: "60 and 88"
Useful for reaction time calculations

Reverse: 1 mph = 1.467 ft/s

Why use ft/s? Common in ballistics, engineering, and physics problems in the US.

Convert FT/S to MPH →

What is the standard speed limit unit used globally?

Kilometers per hour (km/h) is the most common unit worldwide.

Countries using km/h:

All of Europe
Canada
Australia
Asia (China, Japan, India, etc.)
South America
Africa
~95% of world population

Countries using mph:

United States
United Kingdom (partially—also uses km/h)
Liberia
Myanmar (Burma)

Mixed usage:

UK: Road signs in mph, but cars show both
Ireland: Switched from mph to km/h in 2005

Why the split? Historical reasons and resistance to metrication in some countries.

How fast is light speed in common units?

Speed of light (c) = 299,792,458 meters per second (exact by definition)

In common units:

186,282 miles per second (exact conversion)
670,616,629 mph (miles per hour)
1,079,252,849 km/h (kilometers per hour)
0.3 meters per nanosecond (useful in computing)

Practical examples:

Light travels Earth's circumference ~7.5 times per second
Sunlight reaches Earth in ~8 minutes 20 seconds
Light from nearest star (Proxima Centauri) takes 4.2 years

Nothing travels faster than light in a vacuum (fundamental physics limit).

Light-year: Distance light travels in one year ≈ 5.88 trillion miles (9.46 trillion km)

How do I calculate average speed?

Formula: Average Speed = Total Distance ÷ Total Time

Steps:

Add up all distances traveled (use consistent units)
Add up all time taken (convert to same unit)
Divide distance by time

Example 1 - Simple:

Distance: 120 miles
Time: 2 hours
Average speed: 120 ÷ 2 = 60 mph

Example 2 - Multiple segments:

Segment 1: 30 miles in 0.5 hours
Segment 2: 45 miles in 1 hour
Total: 75 miles in 1.5 hours
Average: 75 ÷ 1.5 = 50 mph

Common mistake: Don't average the speeds! If you drive 60 mph then 40 mph, average speed ≠ 50 mph (depends on distance/time of each segment).

Units must match:

Miles ÷ hours = mph
Kilometers ÷ hours = km/h
Meters ÷ seconds = m/s

What's faster: 100 km/h or 60 mph?

100 km/h is faster than 60 mph.

Conversions:

100 km/h = 62.14 mph
60 mph = 96.56 km/h

Difference: 100 km/h is about 3.5% faster than 60 mph.

Quick comparison guide:

50 km/h ≈ 31 mph
80 km/h ≈ 50 mph
100 km/h ≈ 62 mph
120 km/h ≈ 75 mph
130 km/h ≈ 81 mph

Memory trick: "100 km/h is roughly 60 mph" (slightly over)

Compare Speeds →

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Length Converter → - Miles, kilometers, meters
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Fuel Consumption → - MPG, L/100km

Physics & Engineering:

Acceleration Converter → - m/s², g-force
Frequency Converter → - Hz, RPM

Browse All:

All Converters → - Complete list
Conversion Guides → - Measurement tutorials

Popular Speed Conversion Pairs

Metric to Imperial:

Imperial to Metric:

Maritime & Aviation:

Within Metric:

Start converting now: Select units above or choose a specific conversion pair from our complete list.

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Speed Conversion Table

Print-friendly reference chart

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Unit Symbols

Copy & paste speed symbols

Popular Speed Conversion Pairs

Quick access to the most commonly used speed conversions:

Complete List: All Speed Unit Conversions

Browse all categories →

Complete alphabetical list of all speed conversion pairs. Each conversion page includes formulas, examples, and conversion tables.

Frequently Asked Questions about Speed/

No—ft/s is a smaller unit, so the number is bigger for the same speed.

1 mph = 1.467 ft/s
100 ft/s = 68 mph (the ft/s number is bigger, but it's actually slower than "100 mph") Think of it like inches vs feet: 12 inches = 1 foot. "12" is bigger than "1", but they're the same length. Similarly, "100 ft/s" looks bigger than "68 mph", but they're the same speed.

Helpful Conversion Guides

Learn more about unit conversion with our comprehensive guides. Master speed conversions and explore other measurement systems:

📚 How to Convert Units

Step-by-step guide to unit conversion with practical examples.

🔢 Conversion Formulas

Essential formulas for speed and other conversions.

View All Guides →

Speed Unit Converter

About Speed Conversions

Quick Start: Speed Conversions

Understanding Speed Conversions

Why Speed Conversion Matters

Common Speed Units Explained

Metric System (International)

Imperial / US Customary

Specialized Units

Conversion Quick Reference

Common Conversions

Metric Conversions

Imperial Conversions

Practical Speed Examples

Road Speeds & Driving

Aviation

Maritime

Sports & Athletics

Nature & Animals

Physics & Sound

Common Conversion Mistakes

Mistake 1: Wrong MPH-KM/H Conversion Factor

Mistake 2: Confusing Statute Miles and Nautical Miles

Mistake 3: Mixing Speed Units in Calculations

Mistake 4: Confusing M/S with MPH

Mistake 5: Assuming Speed = Velocity

Mistake 6: Wrong Mach Number Assumptions

Frequently Asked Questions

How many kilometers per hour are in a mile per hour?

How do I convert kilometers per hour to miles per hour?

What is a knot equivalent to in mph?

How do I convert meters per second to miles per hour?

How fast is Mach 1?

What's the difference between speed and velocity?

How do I convert feet per second to miles per hour?

What is the standard speed limit unit used globally?

How fast is light speed in common units?

How do I calculate average speed?

What's faster: 100 km/h or 60 mph?

Related Converters

Popular Speed Conversion Pairs

Popular Speed Conversion Pairs

Complete List: All Speed Unit Conversions

Frequently Asked Questions about Speed/

Is ft/s faster than mph?

What is the speed of sound in ft/s?

How do I convert mph to ft/s in my head?

Why do bullets use ft/s instead of mph?

What is terminal velocity in ft/s?

How fast is 300 ft/s in mph?

What does "subsonic ammo" mean?

How far does a car travel in 1 second at 60 mph?

Can I use ft/s in scientific equations?

What's the difference between ft/s and ft/s²?

Where is km/h primarily used?

Is km/h an SI unit?

How do you convert km/h to mph?

How do you convert km/h to m/s?

What is a good walking speed in km/h?

What is the typical highway speed in km/h?

How fast is 100 km/h?

What speed is considered fast for a car?

Do planes use km/h or mph?

Why doesn't the whole world use km/h?

How accurate are car speedometers in km/h?

Why do planes and ships use knots instead of mph?

Is saying "knots per hour" correct?

How do I convert knots to mph mentally?

What is the fastest speed ever recorded in knots?

Do cars ever use knots?

Why is a nautical mile longer than a statute mile?

How fast is the wind in a hurricane?

What is a "gale" in knots?

How fast is Mach 1 in knots?

What is a sonic boom?

Why did the Concorde stop flying?

Can a car go Mach 1 on land?

What is "Critical Mach Number"?

How do pilots calculate Mach number?

Is Mach 10 possible for aircraft?