Kilometers per hour.
km/h to m/s Converter — km/h to m/s
Convert km/h (km/h) to m/s (m/s) using the exact conversion factor (1 km/h = 0.2777777778 m/s). See the formula, worked examples, conversion table, unit comparison, history, and common uses.
km/h to m/s converter
Converter
Speed Converter
Convert road, aviation, marine, lab, and scientific speed units.
Context values
Some unit families need one extra value for a physically accurate result.
Meters per second.
Result = input x 0.2777777778 / 1.
Speed uses meters per second as the base unit.
Reserved above the conversion cards and below the converter.
About Converting km/h to m/s
km/h and m/s both describe speed, and the conversion matters whenever a maritime or aviation speed (knots) needs to be compared against a road speed (mph). km/h is typically associated with standard road-speed unit worldwide except the US, while m/s is typically associated with standard scientific speed unit worldwide.
Formula
m/s = km/h × 0.277777777778
This factor comes from each unit's defined relationship to the category's base unit: 1 km/h equals 0.277777777778 base units, and 1 m/s equals 1 base unit, so dividing one by the other gives the direct km/h-to-m/s factor of 0.277777777778.
Simple example
1 km/h × 0.2777777778 = 0.2777777778 m/s
1 km/h = 0.2777777778 m/s.
Real-world example
10 km/h × 0.2777777778 = 2.777777778 m/s
10 km/h = 2.777777778 m/s.
Conversion table
| km/h (km/h) | m/s (m/s) |
|---|---|
| 1 km/h | 0.2777777778 m/s |
| 5 km/h | 1.388888889 m/s |
| 10 km/h | 2.777777778 m/s |
| 25 km/h | 6.944444444 m/s |
| 50 km/h | 13.88888889 m/s |
| 100 km/h | 27.77777778 m/s |
Reverse conversion: m/s to km/h
0.2777777778 m/s × 3.6 = 1 km/h
0.2777777778 m/s = 1 km/h.
km/h = m/s × 3.6
km/h vs. m/s
| Aspect | km/h | m/s |
|---|---|---|
| Family | SI-derived (metric) unit | SI derived unit |
| Typical use | Road speed limits and vehicle speedometers outside the US | Scientific and engineering speed/velocity calculations |
| Where it's used | Standard road-speed unit worldwide except the US | Standard scientific speed unit worldwide |
Understanding the km/h
km/h (km/h) measures speed. Kilometers per hour follows directly from the kilometer divided by one hour. It is classified as a SI-derived (metric) unit.
Where it's used: Standard road-speed unit worldwide except the US
Uses of the km/h today
- Road speed limits and vehicle speedometers outside the US
- Weather reporting (wind speed) in most countries
History of the km/h
Km/h is a compound unit with no independent origin story — it follows automatically once the kilometer and hour were each standardized, becoming the default speed unit as metric countries motorized through the 20th century.
Historical origin. km/h was not the invention of a single named person; it developed through the process described above.
Understanding the m/s
m/s (m/s) measures speed. The meter per second is the SI derived unit of speed: one meter of distance per second of time. It is classified as a SI derived unit.
Where it's used: Standard scientific speed unit worldwide
Uses of the m/s today
- Scientific and engineering speed/velocity calculations
- Meteorology (wind speed, alongside km/h and knots)
- Physics education and calculations
History of the m/s
As a coherent SI derived unit, meters per second follows automatically from the meter and second, the SI base units of length and time, without an independent historical origin.
Historical origin. m/s was not the invention of a single named person; it developed through the process described above.
km/h — sources
- BIPM SI Brochure — Non-SI units accepted for use with SI — Basis for compound metric units like km/h.
m/s — sources
- BIPM SI Brochure — Coherent derived units — Defines m/s as the SI unit of speed.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many m/s are in 1 km/h?
1 km/h equals 0.2777777778 m/s, using the exact defined conversion factor rather than an estimate.
How do I convert km/h to m/s?
Multiply the km/h value by 0.2777777778. The converter above does this instantly to whatever precision you set.
How do I convert m/s back to km/h?
Use the reverse factor: 1 m/s equals 3.6 km/h. You can also use the swap control in the converter above to flip the direction instantly.
What is a km/h?
km/h (km/h) measures speed. Kilometers per hour follows directly from the kilometer divided by one hour. It is classified as a SI-derived (metric) unit.
What is a m/s?
m/s (m/s) measures speed. The meter per second is the SI derived unit of speed: one meter of distance per second of time. It is classified as a SI derived unit.
Is the km/h to m/s conversion exact?
Yes. Both km/h and m/s are defined by fixed standards rather than physical artifacts, so the factor of 0.2777777778 used above is exact to as many digits as you choose to display.
Where is the km/h still used today?
Standard road-speed unit worldwide except the US