- Kilometres per hour
:(For the South African airport with IATA code "KMH", see

Johan Pienaar Airport .)The

**kilometre per hour**(American English :**kilometer per hour**) is a unit of bothspeed (scalar) andvelocity (vector). The unit symbol is**km/h**or**km·h**; however, the colloquial abbreviations "kph" and "kmph" are sometimes also used in English-speaking countries, in analogy to^{−1}mph , although these are not in accordance with international scientific standards. In North Americanslang and military usage, km/h (as well as km) is commonly pronounced, and sometimes even written, as**klicks**or**kays**(K's), although these may also be used to refer tokilometre s.The km/h is the worldwide most commonly used speed unit on road signs and car speedometers. Therefore, it is far more common in everyday usage than the proper SI unit of speed, m/s. Along with the kW·h, km/h is the most commonly used metric unit based on the

hour , which is only a "non-SI unit accepted for use with the International System of Units" by the BIPM. [*[*]*http://www.bipm.org/en/si/si_brochure/ BIPM brochure*] (SI reference)**Conversions*** 3.6 km/h ≡ 1 m/s, the

SI derived unit of speed,metre per second

* 1 km/h ≈ 0.277 78 m/s

* 1 km/h ≈ 0.621 37 mph ≈ 0.911 34feet per second

* 1 knot ≡ 1.852 km/h (exactly)

* 1 mile = 1.609344 km (~1.61 km) [*1 yard ≡ 0.9144 m and*]

1 mile = 1760 yards thus

1 mile = 1760 × 0.9144 ÷ 1000 km

* 1 mile per hour = ~1.61 kilometres per hour

* 1 kilometre per hour = ~0.62 miles per hour**ee also***

Orders of magnitude (speed) **References****External links*** [

*http://flauna.org/speed/ The converter*] Online conversions for speed units: km/h, mph, knots, etc.

* [*http://www.odometre.com Online Conversions of Metric and Imperial Units*]

* [*http://www.convert-me.com/en/convert/speed Conversion Calculator for Units of Speed*]

*Wikimedia Foundation.
2010.*

### Look at other dictionaries:

**kilometres per hour**— noun the ratio of the distance traveled (in kilometers) to the time spent traveling (in hours) • Syn: ↑kilometers per hour, ↑kph, ↑km/h • Hypernyms: ↑rate … Useful english dictionary**Miles per hour**— MPH redirects here. For other uses, see MPH (disambiguation). Automobile speedometer, measuring speed in miles per hour on the outer track, and kilometres per hour on the inner track. Miles per hour is an imperial unit of speed expressing the… … Wikipedia**Metre per hour**— (American spelling: meter per hour) is a metric unit of both speed (scalar) and velocity (Vector (geometry)). Its symbol is m/h or m·h−1 (not to be confused with the imperial unit symbol mph. By definition, an object travelling at a speed of 1… … Wikipedia**kilometers per hour**— noun the ratio of the distance traveled (in kilometers) to the time spent traveling (in hours) • Syn: ↑kilometres per hour, ↑kph, ↑km/h • Hypernyms: ↑rate … Useful english dictionary**per**— W1S3 [pə strong pə: $ pər strong pə:r] prep [Date: 1300 1400; : Latin; Origin: through, by ] 1.) per hour/day/week etc during each hour etc ▪ The park attracts 4 million visitors per year. miles/kilometres per hour (=used for measuring speed) ▪ a … Dictionary of contemporary English**hour**— W1S1 [auə US aur] n ▬▬▬▬▬▬▬ 1¦(60 minutes)¦ 2¦(business/work etc)¦ 3 (work) long/regular etc hours 4¦(time of day)¦ 5¦(long time)¦ 6¦(o clock)¦ 7 1300/1530/1805 etc hours 8 by the hour/from hour to hour 9 lunch/din … Dictionary of contemporary English**per**— strong preposition 1 for each: per kilo/gallon/metre etc (=for each kilo etc): Apples are 60 cents per pound. | My car does about 12 miles per litre (=for each litre of petrol) . | per head (=for or by each person): How much food should we allow… … Longman dictionary of contemporary English**per**— It is a sound general rule not to use this Latin word when an English equivalent exists and is idiomatic: it is better, for example, to say The salary is £40,000 a year rather than The salary is £40,000 per year, and We will send the goods by… … Modern English usage**Foot per second**— The foot per second (plural feet per second) is a unit of both speed (scalar) and velocity (vector quantity, which includes direction). It expresses the distance in feet (ft) traveled or displaced, divided by the time in seconds (s, or sec ). The … Wikipedia**Light-hour**— A light hour (also written light hour) is a unit of length. It is the distance travelled by light in vacuum in one hour. Based on the current definition of the metre a light hour is equal to 1,079,252,848,800 metres ( 1.08 Tm).This distance can… … Wikipedia