How to Convert Feet per second to Kilometres per hour (ft/s to km/h)
Speed conversions come up with expressway limits in km/h, foreign car specs in mph and wind speeds reported in knots by the Meteorological Service. This guide shows how to convert feet per second into kilometres per hour by hand, with examples and a quick-reference table.
The conversion
To convert feet per second to kilometres per hour, multiply the value by 1.09728. To go the other way, divide by the same number (or multiply by 0.9113444153). For a quick estimate, multiply by about 1.1.
Kilometres per hour = feet per second × 1.09728
Worked examples
- 3 ft/s = 3.2918 km/h
- 12.5 ft/s = 13.716 km/h
- 75 ft/s = 82.296 km/h
Feet per second to Kilometres per hour table
| Feet per second | Kilometres per hour |
|---|---|
| 1 ft/s | 1.0973 km/h |
| 2 ft/s | 2.1946 km/h |
| 5 ft/s | 5.4864 km/h |
| 10 ft/s | 10.9728 km/h |
| 20 ft/s | 21.9456 km/h |
| 25 ft/s | 27.432 km/h |
| 50 ft/s | 54.864 km/h |
| 100 ft/s | 109.728 km/h |
| 250 ft/s | 274.32 km/h |
| 500 ft/s | 548.64 km/h |
| 1,000 ft/s | 1,097.28 km/h |
Common questions
Is ft/s to km/h exact?
The factors used here are the internationally defined values where they exist; results are rounded for display only.
How do I convert back?
Use the Kilometres per hour to Feet per second converter.
Mistakes to avoid
Mixing similar-sounding units
US and imperial gallons, pints and tons are different sizes, and decimal kilobytes differ from binary kibibytes.
Dropping the units
A bare number without a unit is easy to misread later. Always write the unit with the result.
Forgetting squared and cubed units
Area and volume factors are the length factor squared or cubed, so 1 m² is about 10.76 sq ft, not 3.28.
Background
For everyday use, three or four significant figures are usually enough. Engineering, science and trade documents may need more, and rounding should happen only at the end of a calculation.
Unit conversion is simply multiplication by a fixed ratio. The ratio between two units of the same quantity never changes, so once you know it you can convert any value in either direction.
Many conversion factors are exact by definition. The inch has been defined as exactly 2.54 centimetres since 1959, and the pound as exactly 0.45359237 kilograms, so conversions involving them can be as precise as you need.
For any value, use the Feet per second to Kilometres per hour Converter or browse all speed converters.
Run your own numbers: Feet per second to Kilometres per hour Converter