How to use
• Type your value into appropriate edit box.
• Converter will translate the value into other systems automatically as you type.

Accuracy - number of significant decimal digits:
 Miles per hour [mph][mi/h] Miles per second [mps][mi/s] Yards per second [yps][yd/s] Feet per second [fps][ft/s] Kilometers per hour [km/h][kmh][kph][kmph] Kilometers per second [km/s] Meters per second [m/s] Knot [kn] nautical mile per hour Mach Speed [Ma] (speed of sound) Light Speed [c]
Examples of different speeds
100m Sprint Record 200m Sprint Record 400m Sprint Record 50 km/h 90 km/h 130 km/h Speed of sound Escape Velocity Speed of Light Cheetah speed Space Shuttle To see description put the mouse cursor over left side of this window .

Click left mouse button to input choosen value into converter and start conversion.
50 km/h = 31 mph

Speed limit in built-up areas in most countries of Europe (Poland - 60 km/h, UK - 48 km/h)
90 km/h = 56 mph

Speed limit outside built-up areas in most countries of EU (European Union)
130 km/h = 80 mph

Speed limit on motorways (highways) in most countries of Europe
Speed of sound travel

The speed of sound depends on the properties of the medium through which it travels. In dry air at 59°F (15°C) at the sea level it is equal to 1 Ma (Mach 1 = 1225km/h = 761mph)
Earth Escape Velocity

Escape Velocity is the speed needed to "break free" from a gravitational field of the object (Earth, Sun etc.). The speed needed to leave gravitational field of the Earth is about 11.19 km/s = 25031 mph
Speed Of Light Travel

The speed of light depends on the properties of the medium through which it travels. For example, speed of light in water equals about 3/4 of c. The speed of the light in perfect vacuum equals c = 299,792,458 m/s = 670,616,629 mph
Usain Bolt Record - 100m sprint race

August 16, 2009 Berlin Atletic Championship - Usain Bolt breaks his own world record. He ran 100m in 9.58 seconds !!!. His average speed was 10.4384 m/s.

Previous record: Usain Bolt is the current world record holder in the 100m sprint race - 9.69 seconds. The record has been established August 16,2008 during Beijing Summer Olympic Games. His average speed during the race equals 10.3199 m/s
Fastest land animal speed

Cheetah (Acinonyx jubatus) is the fastest land animal, reaching speed up to 120 kilometres per hour (75 mph)
Space Shuttle On Re-entry

Typical space shuttle on its way back to earth on its way back to Earth during atmospheric reentry is about 17,500mph
Usain Bolt Record - 200m sprint race

August 20, 2009 Berlin Atletic Championship - Usain Bolt breaks his own world record. He ran 200m in 19.19 seconds !!!. His average speed was 10.4221 m/s.

Previous: Current record holder in 200m sprint is Usain Bolt. The record has been broken August 20,2008 during Summer Olympic Games in Beijing (China). Bolt run 19.30 seconds.
Usain Bolt speed during the 200m sprint race : 10.3627 m/s.
Note, average speed in this race was faster then 100m sprint race speed (10.3199 m/s)
Michael Johnson Record

The current world record holder of the 400 m sprint race is Michael Johnson, USA. The record has been broken August 26, 1999 in Seville, Spain. Johnson ran 43.18s.
His average speed during the winning 400m race: 9.2635 m/s
mph vs. kph (km/h) Example
If your speed or velocity is given in miles per hour (mph) and you want to translate it into kilometers per hour (km/h) type your mph value into edit box labeled 'miles per hour'. Convertion will start automatically as you type, translated value in km/h will be displayed in the edit box labeled 'Kilometers per hour'. On the other hand, km/h to mph conversion starts when you type value of km/h in the edit box labeled 'kilometers per hour'.

Fundamental unit of speed in the International System Of Units (SI) is:
meter per second [m/s].
UnitIn meters per second
Kilometer per hour [km/h]0.27(7)
Mile per hour [mph]0.44704
Meter per second [m/s]1
Foot per second [fps]0.3048
Knot [kn]0.514(4)
Mach Speed [Ma]340.27(7)
Speed of light travel [c]299792458

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