Mile per hour to Foot per second Converter
Convert miles per hour to feet per second with our free online speed converter.
Quick Answer
1 Mile per hour = 1.466667 feet per second
Formula: Mile per hour × conversion factor = Foot 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.
Mile per hour to Foot per second Calculator
How to Use the Mile per hour to Foot per second Calculator:
- Enter the value you want to convert in the 'From' field (Mile per hour).
- The converted value in Foot 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 Mile per hour to Foot per second: Step-by-Step Guide
Converting Mile per hour to Foot per second involves multiplying the value by a specific conversion factor, as shown in the formula below.
Formula:
1 Mile per hour = 1.466667 feet per secondExample Calculation:
Convert 60 miles per hour: 60 × 1.466667 = 88 feet 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 Mile per hour and a Foot per second?
Miles per hour (symbol: mph, MPH, or mi/h) is a unit of speed expressing the number of statute miles traveled in one hour.
Formula: Speed (mph) = Distance (miles) ÷ Time (hours)
Mathematical relationships:
- 1 mph = 1.60934 km/h (kilometers per hour)
- 1 mph = 0.44704 m/s (meters per second)
- 1 mph = 1.46667 ft/s (feet per second)
- 1 mph = 0.868976 knots
Key mental math: At 60 mph:
- You travel exactly 1 mile per minute
- You travel 88 feet per second
- You cover about 97 km/h
Why Miles per Hour Works
Intuitive scaling: The numbers align well with human driving speeds:
- Walking: 3-4 mph
- Residential driving: 25-35 mph
- Highway cruising: 60-70 mph
- Fast driving: 80-90 mph
Easy mental math at 60 mph: When driving 60 mph, distance and time calculations become trivial:
- 30 miles away = 30 minutes
- 90 miles away = 90 minutes (1.5 hours)
- 120 miles away = 120 minutes (2 hours)
This makes 60 mph a natural "reference speed" for American drivers.
and Standards
The foot per second is defined as:
US Customary Definition
1 ft/s = the velocity of a body that travels a distance of one foot in a time interval of one second.
Formula: v (ft/s) = distance (feet) / time (seconds)
Exact SI conversion (since 1959 International Yard and Pound Agreement):
- 1 ft/s = 0.3048 m/s (exactly)
- 1 foot = 0.3048 meters (exactly)
Why ft/s Instead of mph?
Time scale appropriateness: Many technical applications involve sub-second events:
- Ballistics: Bullet flight time measured in milliseconds (0.001 seconds)
- Reaction distance: Driver reaction (1-2 seconds) × speed in ft/s = distance in feet
- Hydraulics: Flow velocities through pipes/channels measured continuously, not per hour
Intuitive scale for small objects:
- "Arrow travels 300 ft/s" vs "arrow travels 205 mph"—ft/s gives clearer sense of per-second distance
- Easier mental math: "How far does projectile travel in 0.1 seconds?" → 30 feet (at 300 ft/s)
Engineering calculations: US hydraulic formulas (Manning's, Darcy-Weisbach) use ft/s natively
Standard Conversions
Imperial/US conversions:
- 1 ft/s = 0.681818 mph (or 15/22 mph exactly)
- 1 ft/s = 3,600 feet/hour
- 1 ft/s = 720 feet/minute
Key conversion (memorize):
- 60 mph = 88 ft/s (exactly: 60 × 5,280 ÷ 3,600 = 88)
- 1 mph = 1.46667 ft/s (or 22/15 exactly)
Metric conversions:
- 1 ft/s = 0.3048 m/s (exactly)
- 1 ft/s = 1.09728 km/h
- 1 ft/s = 30.48 cm/s
Marine/aviation:
- 1 ft/s = 0.592484 knots
- 1 ft/s = 0.000888 Mach (at sea level, 68°F)
Relationship to Acceleration
Feet per second squared (ft/s²) measures acceleration:
- Gravity: g = 32.174 ft/s² (standard gravity, often rounded to 32.2 ft/s²)
- Car acceleration: 0-60 mph in 5 seconds = 88 ft/s ÷ 5 = 17.6 ft/s² average
- Comparison: SI gravity = 9.80665 m/s²
Note: The Mile per hour is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Foot per second belongs to the imperial/US customary system.
History of the Mile per hour and Foot per second
Early 19th Century: Railway Origins
1820s-1830s Railway Boom: The first practical use of "miles per hour" appeared in British railway timetables in the 1820s and 1830s. Steam locomotives needed a standardized way to express speed.
Early Rail Speeds:
- 1825: Stockton & Darlington Railway averaged 15 mph (first passenger railway)
- 1830: Liverpool & Manchester Railway achieved 30 mph
- 1848: Railway speed records exceeded 60 mph
Why mph? Britain used statute miles for road distances, making mph the natural choice for rail speed measurement.
Mid-19th Century: Speed Regulation
1865: The "Red Flag Act" (UK): The Locomotive Act of 1865 limited self-propelled vehicles to:
- 4 mph in open country
- 2 mph in towns
- Required a person with a red flag walking ahead
This was the first national speed limit using mph, though it severely hampered early automotive development.
1896: Repeal and Freedom: The red flag requirement was repealed, allowing vehicles up to 14 mph.
Late 19th Century: Automotive Era Begins
1890s-1900s: Early Automobiles: As automobiles emerged, mph naturally became their speed measurement since roads already used miles for distance.
Early Auto Speeds:
- 1894: First automobile race averaged 15 mph (Paris-Rouen)
- 1906: Land speed record reached 127 mph
- 1920s: Typical cars cruised at 40-50 mph
20th Century: Speed Limits and Standards
1934: First US National Speed Limit (informal): Many states adopted 55-65 mph highway limits.
1974: National Maximum Speed Law (US): Energy crisis led Congress to mandate 55 mph nationwide to conserve fuel (1974-1987).
1987-1995: Speed Limits Raised: States regained control; limits increased to 65 mph on rural interstates.
1995-Present: Modern Speed Limits: Federal speed limit repealed. States set own limits:
- Rural interstates: 70-85 mph (Texas has 85 mph zones)
- Urban interstates: 55-70 mph
- Rural highways: 55-65 mph
- Urban streets: 25-45 mph
Global Metrication: The mph Holdouts
1960s-1970s: World Shifts to km/h: Most countries adopted the metric system and switched to km/h:
- Australia: 1974
- Canada: 1977
- Ireland: 2005
- South Africa: 1976
mph Survivors: Only a few countries still use mph:
- United States: All 50 states use mph exclusively
- United Kingdom: Road signs in mph (railways and aviation use km/h or knots)
- Some Caribbean nations: Remnants of British colonial influence
and Evolution
Ancient Feet to Modern Standardization
The foot through history:
- Ancient civilizations: Egyptian, Greek, Roman feet varied (285-335 mm)
- Roman pes: ~296 mm (11.65 inches)—basis for many European feet
- Medieval England: Multiple feet existed regionally (London foot, York foot)
- 1588: Queen Elizabeth I attempted standardization
- 1824: British Imperial system defined foot as 1/3 yard
- 1959: International Yard and Pound Agreement defined 1 foot = 0.3048 meters exactly
The second:
- Originally: 1/86,400 of mean solar day (Earth's rotation)
- 1967: Redefined using cesium-133 atomic transition (9,192,631,770 cycles = 1 second)
- Modern definition independent of Earth's rotation (which varies slightly)
The Foot-Pound-Second (FPS) System
British engineering standard (1800s-1960s):
- Length: foot (ft)
- Mass: pound (lb)
- Time: second (s)
- Force: poundal (1 lb·ft/s²) or pound-force (lbf)
- Energy: foot-poundal or foot-pound-force (ft·lbf)
- Velocity: feet per second (ft/s)
FPS system applications:
- Railway engineering: Train speeds, braking distances
- Ballistics: Muzzle velocity, projectile range calculations
- Hydraulics: Water flow in pipes, channels, rivers
- Structural engineering: Wind loads, beam deflections
Decline and persistence:
- 1960: SI system established internationally
- 1970s-1980s: Most countries transitioned to metric
- US holdout: American industry, construction, and firearms sectors retained FPS
- Current: US ballistics universally uses ft/s; engineering mixed (metric in automotive/aerospace, imperial in civil/construction)
Ballistics and the ft/s Standard
Why ballistics uses ft/s:
- Historical momentum: 19th-century firearms development used FPS system
- Industry standardization: Millions of existing specifications in ft/s
- Practical scale: 1,000-3,000 ft/s range fits projectile velocities well
- Reloading data: Powder charge tables, pressure curves all in imperial units
Ammunition velocity standards (all in ft/s):
- .22 LR: 1,200-1,700 ft/s
- 9mm Luger: 1,100-1,300 ft/s
- .45 ACP: 800-900 ft/s
- .223 Remington / 5.56 NATO: 3,000-3,300 ft/s
- .308 Winchester / 7.62 NATO: 2,600-2,800 ft/s
- .50 BMG: 2,800-3,000 ft/s
Chronograph measurements: All ballistic chronographs (devices measuring projectile speed) display in ft/s in US market.
US Hydraulic Engineering
Manning's Equation (open channel flow): v = (1.49/n) × R^(2/3) × S^(1/2)
Where:
- v = velocity in ft/s
- n = Manning's roughness coefficient
- R = hydraulic radius in feet
- S = channel slope (dimensionless)
Note: The 1.49 coefficient is specific to ft/s (metric version uses 1.0 with m/s)
US civil engineering applications:
- Storm drainage design
- Sanitary sewer sizing
- Irrigation canal design
- River and stream analysis
- Flood control structures
Persistence reason: US infrastructure built over 150+ years using imperial units—retrofitting millions of engineering drawings impractical.
Driver Education and Safety
The "60 mph = 88 ft/s" Rule:
Used universally in US driver education to teach reaction distance:
Reaction time (typical): 1.5 seconds Distance traveled (at 60 mph): 1.5 × 88 = 132 feet before braking begins
Stopping distance breakdown (60 mph on dry pavement):
- Reaction distance: 132 feet (time to perceive, react, move foot to brake)
- Braking distance: ~180 feet (actual braking to stop)
- Total stopping distance: ~312 feet (longer than a football field!)
Why ft/s is better than mph for this:
- Intuitive: "I travel 88 feet every second at highway speed"
- Easy calculation: seconds × ft/s = feet
- Using mph requires: mph × 1.467 × seconds = feet (harder mental math)
Common Uses and Applications: miles per hour vs feet per second
Explore the typical applications for both Mile per hour (imperial/US) and Foot per second (imperial/US) to understand their common contexts.
Common Uses for miles per hour
Road Transportation Standard
Speed Limits: All US road signs display mph:
- Speed Limit 25
- Speed Limit 55
- Speed Limit 70
Speedometers: All vehicles sold in the US have mph as primary scale:
- Digital displays: show mph
- Analog gauges: mph prominently displayed (km/h smaller, if present)
Traffic Enforcement:
- Speed cameras calibrated in mph
- Radar guns measure mph
- Tickets written in mph ("45 mph in a 30 mph zone")
Weather Forecasting
Wind Speed: US weather reports use mph:
- "Winds 10-15 mph"
- "Gusts up to 40 mph"
- "Sustained winds of 75 mph" (hurricane)
Severe Weather Warnings:
- High wind warning: sustained winds 40+ mph
- Hurricane watch: sustained winds 74+ mph expected
- Tornado warning: rotational winds estimated in mph
Weather Apps: US apps default to mph for wind speed.
Aviation Context (Mixed Use)
Airspeed Indicators: Pilots see:
- Knots (nautical miles per hour) - primary in aviation
- Some general aviation planes show mph
Ground Speed: GPS and flight computers often display:
- Knots for professional aviation
- mph option available for private pilots
Weather Briefings: Aviation weather uses knots, but surface winds at some small airports reported in mph.
Sports Performance Measurement
Baseball Pitch Tracking:
- MLB stadiums display pitch speed in mph on scoreboards
- "95 mph fastball"
- Scouting reports use mph
Racing:
- NASCAR: "Averaging 185 mph for the lap"
- Drag racing: "Trap speed 325 mph"
- Land speed records: measured in mph
Speed Skating, Cycling: In US competitions, sometimes reported in mph alongside metric.
Everyday Distance/Time Calculations
Trip Planning: Americans mentally calculate travel time using mph:
- "It's 180 miles, so 3 hours at 60 mph"
- "I average 70 mph on the highway, so 350 miles takes 5 hours"
Fuel Economy Relationship: MPG (miles per gallon) and mph are connected:
- Highway MPG ratings assume 55-65 mph
- Fuel economy drops significantly above 70 mph
Real Estate: Property distance to amenities:
- "20 minutes at 45 mph = about 15 miles"
When to Use feet per second
Across Industries
Ballistics and Firearms
- Ammunition specifications: All US ammo rated in ft/s muzzle velocity
- Chronograph testing: Velocity measurement devices display ft/s
- Ballistic calculators: Trajectory prediction software requires ft/s input
- Reloading data: Powder charge tables show expected ft/s velocities
Archery and Hunting
- Bow performance: IBO (International Bowhunting Organization) speed ratings in ft/s
- Arrow selection: Spine charts factor in bow speed (ft/s)
- Kinetic energy calculations: KE = (arrow weight × velocity²) ÷ 450,240 (weight in grains, velocity in ft/s → energy in foot-pounds)
US Civil Engineering
- Open channel flow: Manning's equation uses ft/s for rivers, canals, drainage
- Storm water management: Inlet design, detention pond sizing
- Sanitary sewer design: Minimum 2 ft/s to prevent settling
- Flood analysis: Peak flow velocities in ft/s
Driver Education and Safety
- Reaction distance teaching: "At 60 mph, you travel 88 feet every second"
- Following distance: "3-second rule" = 3 × 88 = 264 feet at 60 mph
- Crash reconstruction: Skid mark analysis uses ft/s for velocity calculations
Sports Science
- Baseball/softball: Pitch speed tracking (radar guns display ft/s or mph)
- Golf: Launch monitors measure clubhead and ball speed in ft/s
- Track and field: Sprint speeds converted to ft/s for analysis
Aviation (Limited Use)
- Rate of climb/descent: Feet per minute (fpm), but convertible to ft/s
- Ground speed calculations: Sometimes expressed in ft/s for short-field operations
- Note: Aviation primarily uses knots (nautical miles per hour)
Additional Unit Information
About Foot per second (ft/s)
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
Conversion Table: Mile per hour to Foot per second
| Mile per hour (mph) | Foot per second (ft/s) |
|---|---|
| 0.5 | 0.733 |
| 1 | 1.467 |
| 1.5 | 2.2 |
| 2 | 2.933 |
| 5 | 7.333 |
| 10 | 14.667 |
| 25 | 36.667 |
| 50 | 73.333 |
| 100 | 146.667 |
| 250 | 366.667 |
| 500 | 733.333 |
| 1,000 | 1,466.667 |
People Also Ask
How do I convert Mile per hour to Foot per second?
To convert Mile per hour to Foot per second, enter the value in Mile 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 Mile per hour to Foot per second?
The conversion factor depends on the specific relationship between Mile per hour and Foot 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 Foot per second back to Mile per hour?
Yes! You can easily convert Foot per second back to Mile per hour by using the swap button (⇌) in the calculator above, or by visiting our Foot per second to Mile per hour converter page. You can also explore other speed conversions on our category page.
Learn more →What are common uses for Mile per hour and Foot per second?
Mile per hour and Foot 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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Verified Against Authority Standards
All conversion formulas have been verified against international standards and authoritative sources to ensure maximum accuracy and reliability.
National Institute of Standards and Technology — Standards for speed and velocity measurements
Last verified: December 3, 2025