Kilometers per hour can also be referred to as kilometres per hour. Shorthand abbreviations also include kmph, as well as km/h, which is the accepted unit by the International Bureau of Weights and Measurements.
A kilometer is a unit of length, used in the metric system, equivalent to 1,000 meters. The word itself is comprised of the Greek words khilia, which means thousand and metro, meaning count or measure.
About 3.6 km/h equals 1 m/s or the SI unit of speed, and alternately 1 km/h is approximately equal to .277 78 m/s. The nautical unit of speed, referred to as a knot, is exactly proportionate to 1.852 km/h. Converting to the American Standard Units of Measurement, 1 kilometer is equal to approximately 0.621 miles, 1,094 yards or 3,281 feet.
