Millimeters Per Second to Kilometers Per Hour (mm/s to km/h)

1 millimeter per second equals 0.0036 kilometers per hour exactly.

1 millimeter per second = 0.0036 kilometers per hour

How to convert millimeters per second to kilometers per hour

To convert millimeters per second to kilometers per hour, multiply the number of millimeters per second by 0.0036. This factor is exact. To go the other way, multiply kilometers per hour by 277.7777778 (rounded).

kilometers per hour = millimeters per second × 0.0036

Example: 10 millimeters per second = 0.036 kilometers per hour.

About these units

Millimeter Per Second (mm/s)

Metric (SI)Current unit

One thousandth of a meter per second. Used for very slow motion.

Biology and glaciology supply good yardsticks for a millimeter per second. The fastest-swimming bacterium, Thiovulum majus, typically moves at about 0.6 mm/s, and the Jakobshavn Isbrae glacier was recorded flowing at about 0.4 mm/s in 2003. At that rate ice covers roughly 35 meters in a day, because 0.4 mm/s multiplied by 86,400 seconds is about 34.6 m.

Faster, but still slow, is the world record speed of a snail, set in the United Kingdom at 2.75 mm/s, which works out to about 9.9 meters per hour. A millimeter per second is 0.001 m/s, so one meter per second equals 1,000 mm/s. The unit suits slow mechanisms, where meters per second would give awkward decimals, and it sits one step below the centimeter per second in the metric ladder.

1 millimeter per second = 0.001 meters per second (exactly).

Sources: Wikipedia: Orders of magnitude (speed); Wikipedia: Metre per second

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

Related conversions

See all speed units.