Feet per second.
ft/s to km/h Converter — ft/s to km/h
Convert ft/s (ft/s) to km/h (km/h) using the exact conversion factor (1 ft/s = 1.09728 km/h). See the formula, worked examples, conversion table, history, and common uses.
ft/s to km/h 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.
Kilometers per hour.
Result = input x 0.3048 / 0.2777777778.
Speed uses meters per second as the base unit.
Reserved above the conversion cards and below the converter.
About Converting ft/s to km/h
ft/s and km/h both describe speed, and the conversion matters whenever a maritime or aviation speed (knots) needs to be compared against a road speed (mph). Specifically: Feet per second, and kilometers per hour.
Formula
km/h = ft/s × 1.09728
This factor comes from each unit's defined relationship to the category's base unit: 1 ft/s equals 0.3048 base units, and 1 km/h equals 0.277777777778 base units, so dividing one by the other gives the direct ft/s-to-km/h factor of 1.09728.
Simple example
1 ft/s × 1.09728 = 1.09728 km/h
1 ft/s = 1.09728 km/h.
Real-world example
10 ft/s × 1.09728 = 10.9728 km/h
10 ft/s = 10.9728 km/h.
Conversion table
| ft/s (ft/s) | km/h (km/h) |
|---|---|
| 1 ft/s | 1.09728 km/h |
| 5 ft/s | 5.4864 km/h |
| 10 ft/s | 10.9728 km/h |
| 25 ft/s | 27.432 km/h |
| 50 ft/s | 54.864 km/h |
| 100 ft/s | 109.728 km/h |
Reverse conversion: km/h to ft/s
1.09728 km/h × 0.9113444153 = 1 ft/s
1.09728 km/h = 1 ft/s.
ft/s = km/h × 0.911344415281
Understanding the ft/s (ft/s)
Feet per second.
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.
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 km/h are in 1 ft/s?
1 ft/s equals 1.09728 km/h, using the exact defined conversion factor rather than an estimate.
How do I convert ft/s to km/h?
Multiply the ft/s value by 1.09728. The converter above does this instantly to whatever precision you set.
How do I convert km/h back to ft/s?
Use the reverse factor: 1 km/h equals 0.9113444153 ft/s. You can also use the swap control in the converter above to flip the direction instantly.
What is a ft/s?
ft/s (ft/s) is a unit of speed.
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.
Is the ft/s to km/h conversion exact?
Yes. Both ft/s and km/h are defined by fixed standards rather than physical artifacts, so the factor of 1.09728 used above is exact to as many digits as you choose to display.