Kilometers per hour (km/h) is a metric unit of speed that indicates how many kilometres an object travels in one hour. It is widely used in automotive speedometers, cycling, and international aviation.
Understanding Feet per Second (ft/s)
Feet per second (ft/s) is an imperial unit of speed that measures the distance in feet covered each second. It is common in engineering calculations, ballistics, and U.S. construction contexts.
Why Convert Between km/h and ft/s?
When working on projects that involve both metric and imperial specifications—such as designing a vehicle for a global market—you often need to translate speeds accurately. The conversion factor is \(1\ \text{km/h}=0.9113444152814232\ \text{ft/s}\).
Road‑safety analysis in mixed‑unit regions.
Mechanical‑system simulations that require consistent units.
Educational tools that compare metric and imperial systems.
Kilometer per hour to Foot per second Conversion Reference Table
Kilometer per hour (km/h)
Foot per second (ft/s)
0.1
0.0911
0.5
0.4557
1.0
0.9113
2.0
1.8227
5.0
4.5567
10.0
9.1134
20.0
18.2269
50.0
45.5672
100.0
91.1344
500.0
455.6722
1000.0
911.3444
Step‑by‑Step Conversion Example
Convert 10 km/h to feet per second.
Write the known value and the conversion factor.
\[10\ \text{km/h}\times0.9113444152814232\ \frac{\text{ft/s}}{\text{km/h}}\]
Multiply the numbers.
\[10\times0.9113444152814232 = 9.113444152814232\ \text{ft/s}\]
Round to a sensible precision (e.g., three decimal places).
\[\approx 9.113\ \text{ft/s}\]
Therefore, 10 km/h is approximately 9.113 ft/s.
The factor is derived from the exact definitions: 1 km = 1000 m, 1 mile = 5280 ft, and 1 hour = 3600 s. It is accurate to at least 12 significant figures, more than sufficient for engineering work.
Use ft/s when the rest of your calculations are in imperial units (e.g., forces in pounds, distances in feet) or when standards and regulations in your region specify speed in ft/s, such as certain U.S. occupational safety guidelines.
"On fait la science avec des faits, comme on fait une maison avec des pierres ; mais une accumulation de faits n'est pas plus une science qu'un tas de pierres n'est une maison." "Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house." — Henri Poincaré (French Mathematician, Theoretical Physicist & Mining Engineer)