Kilometres Per Hour - History & Definition
Kilometres per hour is the most commonly seen metric unit of speed, being used for road speed limit signs in most countries in the world. Although technically a derivative unit its usefulness as a term for the speed of motor vehicles has perpetuated its widespread use.
1 km/h = 3.6 m/s (metres per second the formal SI unit of speed)
The unit is formally abbreviated by km/h, however kph and kmph are in common use in both the UK and US and can often be seen on car dashboards.
Some Speed Records in Kilometres Per Hour
- Land Speed Record - Thrust SSC (UK) - 1227.986 kph
- Electric Powered Land Speed Record - Buckeye Bullet (US) - 517.942 kph
- Motorcylce Land Speed Record - Top Oil Ack Attack (US) - 605.697 kph
- Rail Speed Record - SNCF TGV POS (F) - 574.80 kph
- Maglev Speed Record - JR-Maglev MLX01 (J) - 581.00 kph
- Water Speed Record - Spirit of Australia (AUS) - 511.13 kph
See our miles per hour page for the speed records in mph