Kilometers per hour.
km/h to ft/s Converter — km/h to ft/s
Convert km/h (km/h) to ft/s (ft/s) using the exact conversion factor (1 km/h = 0.9113444153 ft/s). See the formula, worked examples, conversion table, history, and common uses.
km/h to ft/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.
Feet per second.
Result = input x 0.2777777778 / 0.3048.
Speed uses meters per second as the base unit.
Reserved above the conversion cards and below the converter.
About Converting km/h to ft/s
km/h and ft/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 most often used for road speed limits and vehicle speedometers outside the us.
Formula
ft/s = km/h × 0.911344415281
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 ft/s equals 0.3048 base units, so dividing one by the other gives the direct km/h-to-ft/s factor of 0.911344415281.
Simple example
1 km/h × 0.9113444153 = 0.9113444153 ft/s
1 km/h = 0.9113444153 ft/s.
Real-world example
10 km/h × 0.9113444153 = 9.113444153 ft/s
10 km/h = 9.113444153 ft/s.
Conversion table
| km/h (km/h) | ft/s (ft/s) |
|---|---|
| 1 km/h | 0.9113444153 ft/s |
| 5 km/h | 4.556722076 ft/s |
| 10 km/h | 9.113444153 ft/s |
| 25 km/h | 22.78361038 ft/s |
| 50 km/h | 45.56722076 ft/s |
| 100 km/h | 91.13444153 ft/s |
Reverse conversion: ft/s to km/h
0.9113444153 ft/s × 1.09728 = 1 km/h
0.9113444153 ft/s = 1 km/h.
km/h = ft/s × 1.09728
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 ft/s (ft/s)
Feet per second.
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 ft/s are in 1 km/h?
1 km/h equals 0.9113444153 ft/s, using the exact defined conversion factor rather than an estimate.
How do I convert km/h to ft/s?
Multiply the km/h value by 0.9113444153. The converter above does this instantly to whatever precision you set.
How do I convert ft/s back to km/h?
Use the reverse factor: 1 ft/s equals 1.09728 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 ft/s?
ft/s (ft/s) is a unit of speed.
Is the km/h to ft/s conversion exact?
Yes. Both km/h and ft/s are defined by fixed standards rather than physical artifacts, so the factor of 0.9113444153 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