# Speed unit conversion table

This table contains conversions between almost all speed(velocity) units. Some units of speed(velocity) are common and some are relatively rare. This is a good query tool.  Speed Converter

Name of unitSymbolDefinitionRelation to SI units
footper hourfph≡ 1 ft/h= 8.4 6×10 −5 m/s
footper minutefpm≡ 1 ft/min= 5.08 ×10 −3 m/s
footper secondfps≡ 1 ft/s= 3.048 ×10 −1 m/s
furlongper fortnight ≡ furlong/fortnight1.663 095×10 −4 m/s
inchper houriph≡ 1 in/h= 7.0 5×10 −6m/s
inch per minuteipm≡ 1 in/min= 4.2 3×10 −4m/s
inch per secondips≡ 1 in/s= 2.54 ×10 −2 m/s
kilometre per hourkm/h≡ 1 km/h= 2. 7×10 −1 m/s
knotkn≡ 1 nmi/h = 1.852 km/h= 0.51 4 m/s
knot(Admiralty)kn≡ 1 NM (Adm)/h = 1.853 184 km/h[ citation needed]= 0.514 773 m/s
mach numberMRatio of the speed to the speed of sound [note 1]in the medium (unitless).≈ 340 to 295 m/s
metre per second(SI unit)m/s≡ 1 m/s= 1 m/s
mile per hourmph≡ 1 mi/h= 0.447 04 m/s
mileper minutempm≡ 1 mi/min= 26.8224 m/s
mile per secondmps≡ 1 mi/s= 1 609.344 m/s
speed of lightin vacuumc299 792458 m/s= 299 792458 m/s
speed of soundin airs1225to 1062 km/h(761–660 mph or 661–574 kn) [note 1]340 to 295 m/s
Note
1. ^ Jump up to:abThe speed of sound varies especially with temperature and pressure from about 1225 km/h(761 mph or 661 kn)
in air at sea level to about 1062 km/h(660 mph or 570 kn) at jet altitudes ( 12 200 m or 40 000 ft).