Kilometer per hour to Meter per second Converter
Convert kilometers per hour to meters per second with our free online speed converter.
Quick Answer
1 Kilometer per hour = 0.277778 meters per second
Formula: Kilometer per hour × conversion factor = Meter per second
Use the calculator below for instant, accurate conversions.
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All conversion formulas on UnitsConverter.io have been verified against NIST (National Institute of Standards and Technology) guidelines and international SI standards. Our calculations are accurate to 10 decimal places for standard conversions and use arbitrary precision arithmetic for astronomical units.
Kilometer per hour to Meter per second Calculator
How to Use the Kilometer per hour to Meter per second Calculator:
- Enter the value you want to convert in the 'From' field (Kilometer per hour).
- The converted value in Meter per second will appear automatically in the 'To' field.
- Use the dropdown menus to select different units within the Speed category.
- Click the swap button (⇌) to reverse the conversion direction.
How to Convert Kilometer per hour to Meter per second: Step-by-Step Guide
Converting Kilometer per hour to Meter per second involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Kilometer per hour = 0.277778 meters per secondExample Calculation:
Convert 60 kilometers per hour: 60 × 0.277778 = 16.66667 meters per second
Disclaimer: For Reference Only
These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.
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Need to convert to other speed units?
View all Speed conversions →What is a Kilometer per hour and a Meter per second?
Kilometers per hour (km/h or kph) is a unit of speed expressing the number of kilometers traveled in one hour.
Mathematical definition:
- 1 km/h = 1 kilometer ÷ 1 hour
- 1 km/h = 1,000 meters ÷ 3,600 seconds
- 1 km/h = 0.277777... meters per second (exactly 5/18 m/s)
Exact conversions:
- 1 km/h = 0.621371192 miles per hour (mph)
- 1 mph = 1.609344 km/h (exact, by international agreement)
- 1 km/h = 0.539956803 knots
- 1 km/h = 0.911344415 feet per second
km/h vs. kph: Which is Correct?
Both symbols are used, but km/h is officially preferred:
km/h (preferred):
- Official ISO 80000 standard notation
- Recommended by International Bureau of Weights and Measures (BIPM)
- Used in scientific literature, official road signs in most countries
- Visually clearer: explicitly shows "kilometers" and "hour"
kph (informal):
- Common in casual conversation and older signage
- Shorter and quicker to type
- Still widely understood globally
- Used by some speedometer manufacturers
In practice: Road signs in most countries use "km/h," but people often say "kph" when speaking. Both are universally understood, and you'll never cause confusion using either.
and Standards
The meter per second is defined as:
SI Definition
1 m/s = the velocity of a body that travels a distance of one meter in a time interval of one second.
Formula: v (m/s) = distance (m) / time (s)
SI coherence: The meter per second is a coherent derived unit, meaning it's derived directly from SI base units (meter and second) without numerical factors other than 1.
Why m/s is the "Standard"
Coherent unit integration: Physics equations work directly without conversion factors:
- Force: F = ma → 1 Newton = 1 kg × 1 m/s² (acceleration in m/s²)
- Momentum: p = mv → 1 kg·m/s (velocity in m/s)
- Kinetic energy: KE = ½mv² → 1 Joule = 1 kg × (1 m/s)²
- Power: P = Fv → 1 Watt = 1 N × 1 m/s
If you used km/h or mph, every equation would need messy conversion factors. Using m/s keeps mathematics clean and consistent across all branches of physics and engineering.
Standard Conversions
Metric conversions:
- 1 m/s = 3.6 km/h (exactly, since 1 hour = 3,600 seconds)
- 1 m/s = 0.001 km/s (kilometer per second)
- 1 m/s = 100 cm/s (centimeter per second)
- 1 m/s = 1,000 mm/s (millimeter per second)
Imperial/US conversions:
- 1 m/s = 3.28084 ft/s (feet per second)
- 1 m/s = 2.23694 mph (miles per hour)
- 1 m/s = 196.850 ft/min (feet per minute)
Marine/aviation:
- 1 m/s = 1.94384 knots (nautical miles per hour)
- 1 m/s = 0.00291545 Mach (at sea level, 15°C standard atmosphere)
Relationship to Acceleration
Meters per second squared (m/s²) measures acceleration (rate of change of velocity):
- Gravity: g = 9.8 m/s² (velocity increases 9.8 m/s every second when falling)
- Car acceleration: 0-100 km/h in 5 seconds = average 5.6 m/s² acceleration
- Space shuttle launch: ~30 m/s² (3g) maximum acceleration
Note: The Kilometer per hour is part of the metric (SI) system, primarily used globally in science and trade. The Meter per second belongs to the metric (SI) system.
History of the Kilometer per hour and Meter per second
Kilometers per hour became a common unit of speed with the widespread adoption of the metric system for distance (kilometer) and the standard use of hours for time measurement, particularly following the advent of automobiles and trains where measuring such speeds became practical and necessary.
The Railway Origins (1840s-1860s)
European railways drive initial adoption:
The kilometer per hour emerged naturally from European railway expansion in the mid-1800s:
1840s France: The French railway network, expanding rapidly after the opening of the Paris-Rouen line in 1843, used km/h for all timetable planning. Railway engineers found that:
- Distance calculations were straightforward: 100 km at 50 km/h = 2 hours
- Hourly speeds aligned perfectly with clock-based scheduling
- Metric integration simplified track maintenance and construction measurements
1850s-1860s Central Europe: Germany, Belgium, Austria-Hungary, and Italy adopted km/h as their railway systems developed, creating a cohesive Central European railway network with standardized speed measurements.
Why not meters per second? While m/s is the SI base unit, railway engineers found it impractical:
- 27.8 m/s is harder to visualize than 100 km/h
- Hourly distances matched operational planning horizons
- Passengers understood "kilometers per hour" intuitively
The Automobile Revolution (1900s-1920s)
Cars cement km/h as the dominant standard:
1900-1910: European automobile manufacturers (Peugeot, Renault, Daimler, Benz) designed speedometers calibrated exclusively in km/h. By 1910, virtually all cars sold in continental Europe displayed km/h.
Contrasting British approach: British and American manufacturers used mph, creating a lasting divide that persists today.
1920s standardization: As road construction accelerated, European governments posted speed limits in km/h:
- France: 30 km/h in cities (1922)
- Germany: Various limits by region (Autobahn sections later unrestricted)
- Switzerland: 40 km/h urban limit (1925)
Global Metrication Wave (1960s-1980s)
The world switches from mph to km/h:
1951: Japan became the first major non-European nation to adopt km/h comprehensively for all road transport.
1974: Australia converted from mph to km/h on July 1, 1974 (metric changeover day). All speed limit signs were changed overnight, and speedometers were replaced or modified over the following years.
1977: Canada completed metrication, switching road signs from mph to km/h. The conversion created temporary confusion near the US border, where speeds suddenly appeared numerically higher (60 mph became 100 km/h).
1977: India switched to km/h as part of broader metrication efforts.
1980s: Most remaining countries completed conversion to km/h, with notable exceptions:
- United States: Retained mph despite brief 1970s metric push
- United Kingdom: Officially retained mph for roads, though rail increasingly uses km/h
- Myanmar (Burma): Uses mph but is considering metrication
Modern Global Standard (2000s-Present)
Today's landscape:
195+ countries use km/h as their legal road speed standard, representing approximately 95% of the global population.
Only 3 mph holdouts:
- United States (population: 330+ million)
- United Kingdom (population: 67+ million)
- Myanmar (population: 54+ million)
Notable exception—UK railways: British rail networks increasingly use km/h for high-speed lines (HS1 Channel Tunnel Rail Link operates in km/h), though track mile markers remain.
and Evolution
The Metric System Birth (1790s)
French Revolution context: Pre-revolutionary France had hundreds of different units varying by region and trade, causing economic chaos and fraud. The revolutionary government sought rational, universal standards.
The meter (1793):
- Defined as one ten-millionth (1/10,000,000) of the distance from the North Pole to the Equator through Paris
- Physical standard: platinum bar stored in Paris
- Intent: Based on Earth itself, accessible to all nations, unchanging
The second:
- Already standardized internationally as 1/86,400 of a mean solar day
- Based on Earth's rotation (later refined with atomic clocks)
Natural combination: Scientists and engineers naturally combined meters and seconds to express velocity, though initially various fractional units appeared (cm/s in CGS system, km/h for transportation).
19th Century: Scientific Standardization
CGS system (1860s-1870s):
- Centimeter-gram-second system popular in physics
- Velocity often expressed in cm/s (centimeters per second)
- Used in electromagnetism, thermodynamics, fluid dynamics
MKS system (late 1800s):
- Meter-kilogram-second system proposed by Giovanni Giorgi (1901)
- m/s became the practical velocity unit for engineering
- Better suited to human-scale measurements than cm/s
Metre Convention (1875):
- Treaty of the Metre established International Bureau of Weights and Measures (BIPM)
- Standardized meter and kilogram across signatory nations
- Enabled consistent velocity measurements internationally—critical for:
- Ballistics and military applications
- Railway engineering (train speeds, braking distances)
- Early aeronautics and automotive engineering
SI System Adoption (1960)
11th General Conference on Weights and Measures (CGPM, 1960):
- Established the International System of Units (SI)
- Formally designated m/s as the coherent derived unit for velocity
- Unified previously fragmented metric systems (CGS, MKS, MTS)
Coherence principle: SI units multiply and divide to form other SI units without numerical factors:
- Velocity (m/s) = distance (m) / time (s)
- Acceleration (m/s²) = velocity (m/s) / time (s)
- Force (N = kg·m/s²) = mass (kg) × acceleration (m/s²)
- Momentum (kg·m/s) = mass (kg) × velocity (m/s)
Global adoption timeline:
- 1960s-1970s: Scientific community worldwide adopts SI
- 1970s-1980s: Most countries transition official measurements to SI
- 1990s-2000s: International standards (ISO, IEC) require SI units
- Current: ~195 countries use metric system officially; US, Liberia, Myanmar hold out for general use but use SI in science
The Speed of Light Definition (1983)
17th CGPM (1983): Redefined the meter based on the speed of light:
- Speed of light in vacuum: c = 299,792,458 m/s (exactly, by definition)
- The meter is now: the length of the path traveled by light in vacuum during a time interval of 1/299,792,458 of a second
- The second is defined by atomic clocks (cesium-133 hyperfine transition)
Implications:
- Fundamental constant traceability: m/s is now based on fundamental physics (speed of light), not human artifacts (meter bar)
- Ultimate precision: Velocity measurements as accurate as atomic time measurements
- Universal standard: Same meter per second measurement anywhere in universe
Common Uses and Applications: kilometers per hour vs meters per second
Explore the typical applications for both Kilometer per hour (metric) and Meter per second (metric) to understand their common contexts.
Common Uses for kilometers per hour
Road Traffic Worldwide
The most common unit for speed limits and vehicle speeds (speedometers) worldwide, except in countries like the US and UK.
Global speedometer standard:
- 195+ countries require speedometers calibrated in km/h
- Dual displays common in mph-primary countries (UK cars show both mph and km/h)
- Import vehicles often need speedometer conversion or overlay decals
Speed enforcement:
- Fixed speed cameras display limits in km/h globally
- Radar guns used by police calibrated in km/h in metric countries
- GPS navigation systems default to km/h in most regions (user-changeable)
Driver education:
- Driving schools in km/h countries teach speed estimation in km/h
- Stopping distances calculated using km/h (e.g., "at 100 km/h, stopping distance is approximately 100 meters on dry pavement")
Meteorology and Weather Reports
Often used in public weather forecasts to report wind speeds, especially in metric countries.
Daily weather forecasts:
- TV and radio: "Winds gusting up to 60 km/h expected this afternoon"
- Weather apps: Display wind speed in km/h by default in most countries
- Weather warnings: "Wind advisory in effect for sustained winds of 50-70 km/h"
Severe weather:
- Tropical cyclone tracking: "System intensifying to 180 km/h sustained winds"
- Tornado warnings: While some regions use mph, many use km/h for consistency
- Storm surge modeling: Wind speeds in km/h used for prediction models
Aviation weather (METAR reports):
- Actually use knots (nautical miles per hour) as the international standard, but public-facing forecasts convert to km/h for general audiences
Navigation and Maritime Use
Used alongside other units like knots in some aviation and maritime contexts, although less common than knots for primary navigation.
Maritime context:
- Recreational boating: Many countries display boat speeds in km/h on consumer GPS units
- Ship traffic services: Professional shipping uses knots, but coastal authorities may communicate speeds to recreational vessels in km/h
- Current speeds: Ocean and river current speeds sometimes expressed in km/h for public understanding
Aviation (limited use):
- General aviation: Some small aircraft in Europe display airspeed in km/h
- Groundspeed: GPS navigation sometimes shows groundspeed in km/h for pilots' situational awareness
- Professional aviation: Knots remain the global standard for airspeed and navigation
Sports and Athletics
Sometimes used to describe speeds in cycling, skiing, or running over longer distances.
Cycling:
- Professional race coverage: "The peloton is maintaining 45 km/h on the flat sections"
- Bike computers: Display current speed, average speed, and maximum speed in km/h
- Training metrics: Cyclists track average speeds to gauge fitness improvements
Running:
- Treadmill displays: Often show speed in km/h (especially in metric countries)
- GPS running watches: Can display pace as min/km or speed as km/h
- Race commentary: "The lead pack is running at approximately 21 km/h pace"
Skiing and snowboarding:
- Speed skiing competitions: Measured in km/h (world record: 254.958 km/h, 2016)
- Ski resort speed checks: Display current speed in km/h at base of runs
- Avalanche speeds: "Avalanches can reach 130 km/h in steep terrain"
Other sports:
- Tennis serve speeds: Displayed in km/h globally (fastest recorded: 263 km/h by Sam Groth, 2012)
- Baseball pitch speeds: In metric countries, displayed as km/h (~150 km/h for fast pitches)
- Golf ball speed: Club head and ball speeds measured in km/h in some markets
Scientific and Engineering Applications
Used in physics education, engineering calculations, and scientific research where metric units are standard:
Physics education:
- Introductory kinematics: "A car accelerates from 0 to 100 km/h in 8 seconds—calculate acceleration"
- Energy calculations: Kinetic energy problems often use km/h, then convert to m/s for SI calculations
- Momentum problems: "Two vehicles collide—one traveling at 60 km/h, the other at 80 km/h"
Wind engineering:
- Building design: Wind load calculations use km/h for reference wind speeds
- Bridge engineering: Suspension bridges designed to withstand winds of 150+ km/h
Transportation planning:
- Traffic flow modeling: Simulations use km/h for vehicle speeds
- Capacity analysis: "This highway section can accommodate 2,000 vehicles per hour at 100 km/h"
- Emission modeling: Fuel consumption and emissions vary significantly by speed (optimal efficiency typically 80-90 km/h for modern cars)
Climate science:
- Atmospheric circulation: Jet stream speeds measured in km/h
- Hurricane research: Storm tracking and intensity analysis
Consumer Products and Specifications
Speed ratings and specifications:
Tires:
- Speed ratings: European tire speed codes (e.g., "H-rated: 210 km/h maximum")
- Winter tire testing: Performance ratings at various speeds in km/h
Electric scooters and e-bikes:
- Maximum speed limits: Regulations often specify "limited to 25 km/h" (common EU e-bike limit)
- Product specifications: "Top speed: 30 km/h" on consumer packaging
Drones:
- Maximum flight speed: "Can reach 68 km/h in Sport Mode"
- Return-to-home speed: Typically 30-50 km/h for consumer drones
Recreational vehicles:
- Golf carts: Typically 20-25 km/h maximum
- ATVs and UTVs: Specified in km/h in metric markets
When to Use meters per second
Across Industries
Physics and Scientific Research
- Fundamental constant: All velocity measurements in research papers reported in m/s
- Kinematics: Position, velocity, acceleration equations use m/s and m/s²
- Dynamics: Force, momentum, energy calculations require m/s for SI coherence
- Relativity: Velocities expressed as fractions of c (speed of light in m/s)
Engineering
- Mechanical engineering: Shaft speeds, piston velocities, fluid flow rates in m/s
- Civil engineering: Wind loads, water flow in channels, traffic flow modeling
- Aerospace engineering: Aircraft speeds, rocket velocities, orbital mechanics
- Automotive engineering: Crash testing, braking distances, aerodynamic analysis
Meteorology and Climate Science
- Wind speed: Anemometers calibrated in m/s, weather models use m/s internally
- Storm classification: Hurricane/typhoon wind speeds in m/s (Saffir-Simpson scale)
- Atmospheric circulation: Jet stream velocities, air mass movements
- Ocean currents: Surface and deep ocean current speeds in m/s
Sports Science and Biomechanics
- Performance analysis: Sprint speeds, swimming velocities, ball speeds
- Equipment testing: Golf club head speed, tennis racket velocity, baseball pitch speed
- Injury prevention: Impact velocities, deceleration rates during collisions
- Training optimization: Treadmill speeds, cycling power-to-velocity relationships
Robotics and Automation
- Motion control: Robot arm velocities, conveyor belt speeds
- Autonomous vehicles: Speed sensing, collision avoidance calculations
- Drones: Flight speed control, stability algorithms
- Manufacturing: CNC machine tool speeds, assembly line velocities
Additional Unit Information
About Kilometer per hour (km/h)
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.
Is km/h an SI unit?
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.
About Meter per second (m/s)
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).
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)
What's the difference between speed and velocity?
Speed: Magnitude only (scalar) — how fast you're moving Velocity: Magnitude + direction (vector) — how fast + which way
Example:
- Speed: "The car is traveling at 30 m/s"
- Velocity: "The car is traveling at 30 m/s north" or "30 m/s at 45° from the x-axis"
In physics:
- Both measured in m/s
- Average speed = total distance / time
- Average velocity = displacement / time (can be zero if you return to start!)
Practical:
- Everyday language often uses "speed" for both concepts
- Physics problems require careful distinction
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
Conversion Table: Kilometer per hour to Meter per second
| Kilometer per hour (km/h) | Meter per second (m/s) |
|---|---|
| 0.5 | 0.139 |
| 1 | 0.278 |
| 1.5 | 0.417 |
| 2 | 0.556 |
| 5 | 1.389 |
| 10 | 2.778 |
| 25 | 6.944 |
| 50 | 13.889 |
| 100 | 27.778 |
| 250 | 69.444 |
| 500 | 138.889 |
| 1,000 | 277.778 |
People Also Ask
How do I convert Kilometer per hour to Meter per second?
To convert Kilometer per hour to Meter per second, enter the value in Kilometer per hour in the calculator above. The conversion will happen automatically. Use our free online converter for instant and accurate results. You can also visit our speed converter page to convert between other units in this category.
Learn more →What is the conversion factor from Kilometer per hour to Meter per second?
The conversion factor depends on the specific relationship between Kilometer per hour and Meter per second. You can find the exact conversion formula and factor on this page. Our calculator handles all calculations automatically. See the conversion table above for common values.
Can I convert Meter per second back to Kilometer per hour?
Yes! You can easily convert Meter per second back to Kilometer per hour by using the swap button (⇌) in the calculator above, or by visiting our Meter per second to Kilometer per hour converter page. You can also explore other speed conversions on our category page.
Learn more →What are common uses for Kilometer per hour and Meter per second?
Kilometer per hour and Meter per second are both standard units used in speed measurements. They are commonly used in various applications including engineering, construction, cooking, and scientific research. Browse our speed converter for more conversion options.
For more speed conversion questions, visit our FAQ page or explore our conversion guides.
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Last verified: December 3, 2025