Kilometers Per Hour to Meters Per Second (km/h to m/s)

1 kilometer per hour equals 0.2777777778 meters per second (rounded).

1 kilometer per hour = 0.2777777778 meters per second

How to convert kilometers per hour to meters per second

To convert kilometers per hour to meters per second, multiply the number of kilometers per hour by 0.2777777778. The factor is rounded to 10 significant digits. To go the other way, multiply meters per second by 3.6.

meters per second = kilometers per hour × 0.2777777778

Example: 10 kilometers per hour = 2.777777778 meters per second.

About these units

Kilometer Per Hour (km/h)

Metric (SI)Current unit

The standard unit for road speeds in most countries: 1 km/h is about 0.2778 m/s.

Myriameters per hour came first, at least in French. Although the meter was defined in 1799, speeds were initially quoted using the myriameter of 10,000 meters, and the phrase myriamètres par heure appears in 1802. The Dutch adopted the kilometer in 1817 under the name mijl. English abbreviations only appeared in the late nineteenth century, and many competing forms followed, from k. p. h. in 1889 to KMPH in 1940. Reuters and The Economist still prefer kph.

SI treats km/h as a unit symbol, not an abbreviation, and it is the generally preferred form. The European Union required SI usage in 1972, and a 1975 directive requires km/h on speedometers in all languages. In the United States a 1988 NHTSA rule allowed km/h on speedometers. Exactly 3.6 km/h make 1 m/s, one mile per hour is exactly 1.609344 km/h, and one knot is exactly 1.852 km/h. Road signs and speed limits in most of the world use it.

1 kilometer per hour = 0.2777777778 meters per second (approximately).

Sources: Wikipedia: Kilometres per hour; NIST Guide to the SI, Appendix B.8: conversion factors

Meter Per Second (m/s)

Metric (SI)Current unit

The SI unit of speed. Walking pace is about 1.4 m/s; a sprinter reaches roughly 10 m/s.

Official standing arrived in 1960, when the CGPM established the SI and made the meter per second the unit for speed and velocity. Before that, feet per second, miles per hour and knots were more common, depending on region and trade. One proposal gave 1 m/s its own name, the benz, after Karl Benz, but it was rejected and never caught on, so the unit is still written as a plain ratio of meter to second.

The meter is now defined by the distance light travels in a vacuum in 1/299,792,458 of a second, and the second by the vibration of caesium atoms, so the meter per second rests on two physical standards. Exactly 3.6 km/h make 1 m/s, and it equals about 2.2369 mph or 1.9438 knots. For scale, sound travels at about 343 m/s in dry air at 20 °C, and Chuck Yeager's Bell X-1 reached about 361 m/s, Mach 1.06, in October 1947. Physics and engineering use the unit almost exclusively.

The meter per second is the reference unit for speed on this site.

Sources: Wikipedia: Metre per second; NIST: the meter and the SI redefinition; Wikipedia: Sound barrier

Related conversions

See all speed units.