Convert speed units — km/h, mph, m/s, knots, Mach.
| Unit | Name | Value |
|---|---|---|
| m/s | Meter per Second | 0.3048 |
| km/h | Kilometer per Hour | 1.0972791 |
| mph | Mile per Hour | 0.68181818 |
| kn | Knot | 0.59248431 |
| Mach | Mach | 0.0008957066 |
Common foot per second values converted to mile per hour — factor: 1 ft/s = 0.6818 mph
| Foot per Second (ft/s) | Mile per Hour (mph) | Context |
|---|---|---|
| 1 ft/s | 0.6818 mph | Very slow |
| 5 ft/s | 3.409 mph | Walk |
| 10 ft/s | 6.818 mph | Jog |
| 20 ft/s | 13.64 mph | Sprint |
| 50 ft/s | 34.09 mph | Fast sprint |
| 88 ft/s | 60 mph | 60 mph car |
| 100 ft/s | 68.18 mph | 60 mph car |
| 147 ft/s | 100.2 mph | 100 mph car |
| 500 ft/s | 340.9 mph | Racing car |
| 880 ft/s | 600 mph | 600 mph jet |
| 1,000 ft/s | 681.8 mph | High-speed jet |
| 1,125 ft/s | 767 mph | Speed of sound |
| 2,200 ft/s | 1,500 mph | Rifle bullet |
| 3,000 ft/s | 2,045 mph | Fast bullet |
| 5,000 ft/s | 3,409 mph | Rocket |
Converting foot per second to mile per hour is essential for drivers, pilots, engineers, and scientists working across different measurement systems. Road speed limits, aviation airspeed, nautical navigation, and physics calculations each use different speed units, making quick and accurate conversion a practical everyday skill.
Key reference points: 5 ft/s = 3.409 mph and 10 ft/s = 6.818 mph. At higher speeds, 100 ft/s = 68.18 mph. For reverse conversion, multiply mph values by 1.467 to get back to ft/s.
All conversions use the internationally recognized factor of exactly 1 ft/s = 0.6818 mph. Calculations are performed in IEEE 754 double-precision floating point, giving accuracy to at least 8 significant figures — more than sufficient for any practical application.
Formula: Mile per Hour = Foot per Second × 0.68181818
Multiply any foot per second value by 0.68181818 to get mile per hour. One foot per second equals 0.68181818 mph.
Reverse: Foot per Second = Mile per Hour × 1.4666667
ft/s × 0.6818 = mph. Round to × 0.68.
Classic anchor: 88 ft/s = exactly 60 mph. Memorize this.
mph × 1.4667 = ft/s.
Rates bullet muzzle velocity in feet per second for ammunition comparisons.
Measures duct air velocity in feet per second for airflow design.
Evaluates arrow speed in fps to optimize bow setup and shooting form.
Sets character movement speeds in fps for physics-based game engines.
Calculates water hammer and pipe flow velocities in ft/s.
References pitch speed, puck speed, and serve speed in fps for broadcast.
Feet per second is an Imperial unit of speed equal to exactly 0.3048 m/s. It was in common use in Britain and America from the 17th century, particularly in ballistics and military applications.
ft/s remains the standard in US ballistics: bullet velocities, muzzle speeds, and arrow velocities are universally quoted in feet per second. It also appears in HVAC airflow measurements and some engineering contexts.
Interesting fact: A typical rifle bullet travels at 900-1,200 ft/s (270-370 m/s). The speed of sound at sea level is approximately 1,125 ft/s.
Miles per hour traces its roots to Imperial Britain, where the mile was standardized as 1,760 yards in the 18th century. The UK adopted mph for road use and exported it to its colonies, explaining why the US, UK, and a handful of other nations still use it.
The United States, United Kingdom, Liberia, and Myanmar are the primary countries still using mph for road speeds. US Interstate speed limits are typically 65-75 mph, while UK motorways are limited to 70 mph.
Interesting fact: The world's fastest production car, the Bugatti Chiron Super Sport, reaches 304 mph (490 km/h). The US air speed record stands at 2,193 mph set by the SR-71 Blackbird.