Kilometers per hour.
km/h to Mile per Seconds Converter — km/h to mi/s
Convert km/h (km/h) to Mile per Seconds (mi/s) using the exact conversion factor (1 km/h = 0.0001726031 mile per seconds). See the formula, worked examples, conversion table, history, and common uses.
km/h to Mile per Seconds 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.
Distance divided by time.
Result = input x 0.2777777778 / 1609.344.
Speed uses meters per second as the base unit.
Reserved above the conversion cards and below the converter.
About Converting km/h to Mile per Seconds
km/h and Mile per Seconds 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 most often used for road speed limits and vehicle speedometers outside the us.
Formula
mile per seconds = km/h × 0.000172603108955
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 mile per seconds equals 1609.344 base units, so dividing one by the other gives the direct km/h-to-mile per seconds factor of 0.000172603108955.
Simple example
1 km/h × 0.000172603109 = 0.0001726031 mi/s
1 km/h = 0.0001726031 mile per seconds.
Real-world example
10 km/h × 0.000172603109 = 0.0017260311 mi/s
10 km/h = 0.0017260311 mile per seconds.
Conversion table
| km/h (km/h) | Mile per Seconds (mi/s) |
|---|---|
| 1 km/h | 0.0001726031 mi/s |
| 5 km/h | 0.0008630155 mi/s |
| 10 km/h | 0.0017260311 mi/s |
| 25 km/h | 0.0043150777 mi/s |
| 50 km/h | 0.0086301554 mi/s |
| 100 km/h | 0.0172603109 mi/s |
Reverse conversion: Mile per Seconds to km/h
0.0001726031 mi/s × 5793.6384 = 0.9999999481 km/h
0.0001726031 mile per seconds = 0.9999999481 km/h.
km/h = mile per seconds × 5793.6384
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 Mile per Seconds (mi/s)
Distance divided by time.
km/h — sources
- BIPM SI Brochure — Non-SI units accepted for use with SI — Basis for compound metric units like km/h.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many mile per seconds are in 1 km/h?
1 km/h equals 0.0001726031 mile per seconds, using the exact defined conversion factor rather than an estimate.
How do I convert km/h to mile per seconds?
Multiply the km/h value by 0.000172603109. The converter above does this instantly to whatever precision you set.
How do I convert mile per seconds back to km/h?
Use the reverse factor: 1 mile per seconds equals 5,793.6384 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 mile per seconds?
Mile per Seconds (mi/s) is a unit of speed.
Is the km/h to mile per seconds conversion exact?
Yes. Both km/h and mile per seconds are defined by fixed standards rather than physical artifacts, so the factor of 0.000172603109 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