Kilometers Per Hour to Feet Per Second (km/h to ft/s)
1 kilometer per hour equals 0.9113444153 feet per second (rounded).
How to convert kilometers per hour to feet per second
To convert kilometers per hour to feet per second, multiply the number of kilometers per hour by 0.9113444153. The factor is rounded to 10 significant digits. To go the other way, multiply feet per second by 1.09728.
feet per second = kilometers per hour × 0.9113444153
Example: 10 kilometers per hour = 9.113444153 feet per second.
About these units
Kilometer Per Hour (km/h)
The standard unit for road speeds in most countries: 1 km/h is about 0.2778 m/s.
Myriameters per hour came first, at least in French. Although the meter was defined in 1799, speeds were initially quoted using the myriameter of 10,000 meters, and the phrase myriamètres par heure appears in 1802. The Dutch adopted the kilometer in 1817 under the name mijl. English abbreviations only appeared in the late nineteenth century, and many competing forms followed, from k. p. h. in 1889 to KMPH in 1940. Reuters and The Economist still prefer kph.
SI treats km/h as a unit symbol, not an abbreviation, and it is the generally preferred form. The European Union required SI usage in 1972, and a 1975 directive requires km/h on speedometers in all languages. In the United States a 1988 NHTSA rule allowed km/h on speedometers. Exactly 3.6 km/h make 1 m/s, one mile per hour is exactly 1.609344 km/h, and one knot is exactly 1.852 km/h. Road signs and speed limits in most of the world use it.
1 kilometer per hour = 0.2777777778 meters per second (approximately).
Sources: Wikipedia: Kilometres per hour; NIST Guide to the SI, Appendix B.8: conversion factors
Foot Per Second (ft/s)
Exactly 0.3048 m/s. Used for velocity in US engineering, ballistics and fluid flow.
Compound units rarely have a recorded inventor, and the foot per second is a plain example: it is just a foot divided by a second. The foot underneath it began as a body-based length ranging historically from about 250 to 335 millimeters, with ancient Greek and Roman feet near 300 mm. Before the SI arrived in 1960, feet per second, miles per hour and knots were more common than meters per second, depending on region.
The 1959 international agreement fixed the foot at exactly 0.3048 meter, so one foot per second is exactly 0.3048 m/s, about 1.097 km/h or 0.6818 mph. Sound moves at about 1,125 ft/s in dry air at 20 °C, which is 343 m/s. Chuck Yeager's Bell X-1 reached about 361 m/s in 1947, near 1,184 ft/s. The unit remains common in American engineering and science, where lengths are still given in feet and inches.
1 foot per second = 0.3048 meters per second (exactly).
Sources: Wikipedia: Foot per second; Wikipedia: Foot (unit); NIST Guide to the SI, Appendix B.8: conversion factors
Related conversions
- Feet per second to kilometers per hour (reverse)
- Kilometers per hour to meters per second
- Kilometers per hour to miles per hour
- Kilometers per hour to knots
- Kilometers per hour to Mach
- Kilometers per hour to speed of light
- Kilometers per hour to centimeters per second
- Kilometers per hour to millimeters per second
- Kilometers per hour to kilometers per second
- Kilometers per hour to kilometers per minute
- Kilometers per hour to meters per minute
- Kilometers per hour to inches per second
- Kilometers per hour to feet per minute
- Meters per second to feet per second
- Miles per hour to feet per second
- Knots to feet per second
- Mach to feet per second
- Speed of light to feet per second
See all speed units.