Speed conversions
Speed converter for metric, imperial and specialist speed units — kilometres per hour, metres per second, miles per hour, knots, Mach number, feet per second, centimetres per second and the Beaufort wind scale.
The global road-speed unit used in 195 countries
Kilometer per Hour to Meter per Second
1 km/h = 0.2778 m/s
Kilometer per Hour to Mile per Hour
1 km/h = 0.6214 mph
Kilometer per Hour to Knot
1 km/h = 0.54 kn
Kilometer per Hour to Mach
1 km/h = 0.0008163 Ma
Kilometer per Hour to Foot per Second
1 km/h = 0.9113 ft/s
Kilometer per Hour to Centimeter per Second
1 km/h = 27.7778 cm/s
Kilometer per Hour to Yard per Minute
1 km/h = 18.2269 yd/min
Kilometer per Hour to Inch per Minute
1 km/h = 656.685 in/min
Kilometer per Hour to Beaufort Scale
1 km/h = 0.2778 Bft
The SI base speed unit — used in physics and wind measurement
Meter per Second to Kilometer per Hour
1 m/s = 3.6 km/h
Meter per Second to Mile per Hour
1 m/s = 2.23694 mph
Meter per Second to Knot
1 m/s = 1.94384 kn
Meter per Second to Mach
1 m/s = 0.002939 Ma
Meter per Second to Foot per Second
1 m/s = 3.28084 ft/s
Meter per Second to Centimeter per Second
1 m/s = 100 cm/s
Meter per Second to Yard per Minute
1 m/s = 65.6168 yd/min
Meter per Second to Inch per Minute
1 m/s = 2,364.07 in/min
Meter per Second to Beaufort Scale
1 m/s = 1 Bft
The US and UK road-speed unit — 1.609 km/h per mph
Mile per Hour to Kilometer per Hour
1 mph = 1.60934 km/h
Mile per Hour to Meter per Second
1 mph = 0.447 m/s
Mile per Hour to Knot
1 mph = 0.869 kn
Mile per Hour to Mach
1 mph = 0.001314 Ma
Mile per Hour to Foot per Second
1 mph = 1.46667 ft/s
Mile per Hour to Centimeter per Second
1 mph = 44.704 cm/s
Mile per Hour to Yard per Minute
1 mph = 29.3333 yd/min
Mile per Hour to Inch per Minute
1 mph = 1,056.83 in/min
Mile per Hour to Beaufort Scale
1 mph = 0.447 Bft
The standard speed unit in marine and air navigation
Knot to Kilometer per Hour
1 kn = 1.852 km/h
Knot to Meter per Second
1 kn = 0.5144 m/s
Knot to Mile per Hour
1 kn = 1.15078 mph
Knot to Mach
1 kn = 0.001512 Ma
Knot to Foot per Second
1 kn = 1.68781 ft/s
Knot to Centimeter per Second
1 kn = 51.4444 cm/s
Knot to Yard per Minute
1 kn = 33.7562 yd/min
Knot to Inch per Minute
1 kn = 1,216.18 in/min
Knot to Beaufort Scale
1 kn = 0.5144 Bft
Speed relative to the speed of sound — Mach 1 = 1225 km/h
Mach to Kilometer per Hour
1 Ma = 1,225.04 km/h
Mach to Meter per Second
1 Ma = 340.29 m/s
Mach to Mile per Hour
1 Ma = 761.207 mph
Mach to Knot
1 Ma = 661.471 kn
Mach to Foot per Second
1 Ma = 1,116.44 ft/s
Mach to Centimeter per Second
1 Ma = 34,029 cm/s
Mach to Yard per Minute
1 Ma = 22,328.74 yd/min
Mach to Inch per Minute
1 Ma = 804,468.09 in/min
Mach to Beaufort Scale
1 Ma = 340.29 Bft
Used in US engineering, ballistics and older physics texts
Foot per Second to Kilometer per Hour
1 ft/s = 1.09728 km/h
Foot per Second to Meter per Second
1 ft/s = 0.3048 m/s
Foot per Second to Mile per Hour
1 ft/s = 0.6818 mph
Foot per Second to Knot
1 ft/s = 0.5925 kn
Foot per Second to Mach
1 ft/s = 0.0008957 Ma
Foot per Second to Centimeter per Second
1 ft/s = 30.48 cm/s
Foot per Second to Yard per Minute
1 ft/s = 20 yd/min
Foot per Second to Inch per Minute
1 ft/s = 720.567 in/min
Foot per Second to Beaufort Scale
1 ft/s = 0.3048 Bft
Used for slow motion — ocean currents, biology, sedimentation
Centimeter per Second to Kilometer per Hour
1 cm/s = 0.036 km/h
Centimeter per Second to Meter per Second
1 cm/s = 0.01 m/s
Centimeter per Second to Mile per Hour
1 cm/s = 0.02237 mph
Centimeter per Second to Knot
1 cm/s = 0.01944 kn
Centimeter per Second to Mach
1 cm/s = 2.9387e-5 Ma
Centimeter per Second to Foot per Second
1 cm/s = 0.03281 ft/s
Centimeter per Second to Yard per Minute
1 cm/s = 0.6562 yd/min
Centimeter per Second to Inch per Minute
1 cm/s = 23.6407 in/min
Centimeter per Second to Beaufort Scale
1 cm/s = 0.01 Bft
Used in textile manufacturing and some US industrial settings
Yard per Minute to Kilometer per Hour
1 yd/min = 0.05486 km/h
Yard per Minute to Meter per Second
1 yd/min = 0.01524 m/s
Yard per Minute to Mile per Hour
1 yd/min = 0.03409 mph
Yard per Minute to Knot
1 yd/min = 0.02962 kn
Yard per Minute to Mach
1 yd/min = 4.4785e-5 Ma
Yard per Minute to Foot per Second
1 yd/min = 0.05 ft/s
Yard per Minute to Centimeter per Second
1 yd/min = 1.524 cm/s
Yard per Minute to Inch per Minute
1 yd/min = 36.0284 in/min
Yard per Minute to Beaufort Scale
1 yd/min = 0.01524 Bft
Used in CNC machining and 3D printing feed rates
Inch per Minute to Kilometer per Hour
1 in/min = 0.001523 km/h
Inch per Minute to Meter per Second
1 in/min = 0.000423 m/s
Inch per Minute to Mile per Hour
1 in/min = 0.0009462 mph
Inch per Minute to Knot
1 in/min = 0.0008222 kn
Inch per Minute to Mach
1 in/min = 1.2431e-6 Ma
Inch per Minute to Foot per Second
1 in/min = 0.001388 ft/s
Inch per Minute to Centimeter per Second
1 in/min = 0.0423 cm/s
Inch per Minute to Yard per Minute
1 in/min = 0.02776 yd/min
Inch per Minute to Beaufort Scale
1 in/min = 0.000423 Bft
Empirical wind-force scale from 0 (calm) to 12 (hurricane)
Beaufort Scale to Kilometer per Hour
1 Bft = 3.6 km/h
Beaufort Scale to Meter per Second
1 Bft = 1 m/s
Beaufort Scale to Mile per Hour
1 Bft = 2.23694 mph
Beaufort Scale to Knot
1 Bft = 1.94384 kn
Beaufort Scale to Mach
1 Bft = 0.002939 Ma
Beaufort Scale to Foot per Second
1 Bft = 3.28084 ft/s
Beaufort Scale to Centimeter per Second
1 Bft = 100 cm/s
Beaufort Scale to Yard per Minute
1 Bft = 65.6168 yd/min
Beaufort Scale to Inch per Minute
1 Bft = 2,364.07 in/min
Tips for speed conversions
1 m/s = 3.6 km/h. A common multiplier in physics problems.
Car speedometers: km/h in most of the world, mph in US and UK (with km/h on EU sold cars).
Knots are used in aviation and marine. 1 knot = 1.852 km/h.
Mach is the ratio of an object's speed to the local speed of sound. Mach 1 varies with altitude and temperature.
Common mistakes to avoid
Forgetting to divide by 3.6 when going from km/h to m/s.
Reading a US speedometer as km/h — 70 mph is 112 km/h.
Treating Mach as a constant speed — sound speed changes with altitude (340 m/s at sea level, 295 m/s at 11 km).
Confusing speed (m/s) with velocity (m/s with direction) in physics.
Learn about each unit
Full encyclopedia page for every speed unit — definition, history, uses, tips.