What is the Speed Conversion Calculator?
This tool converts a speed from one unit to another among the five most common units: meters per second (m/s), kilometers per hour (km/h), miles per hour (mph), feet per second (ft/s) and knots (kn). It is universal — it relies only on fixed physical conversion factors, so it works the same everywhere in the world.
How to use it
Enter the numeric speed value, choose the unit you are converting from, then choose the unit you want to convert to. The calculator shows the converted value plus the equivalent in meters per second so you always have a base reference.
The formula explained
Every unit is defined by how many meters per second it represents. The known factors are: 1 m/s = 1, 1 km/h = 0.27778 m/s, 1 mph = 0.44704 m/s, 1 ft/s = 0.3048 m/s, and 1 kn = 0.51444 m/s. The conversion is a two-step process: first multiply the input by the "from" factor to get a base value in m/s, then divide that by the "to" factor to express it in the target unit.
$$\text{result} = \frac{\text{value} \times f_{\text{from}}}{f_{\text{to}}}$$This can be written as two steps:
$$v_{m/s} = \text{value} \times f_{\text{from}}$$$$\text{result} = \frac{v_{m/s}}{f_{\text{to}}}$$
Worked example
Convert 100 km/h to mph. First to base: \(100 \times 0.27778 = 27.778\) m/s. Then to mph: \(27.778 \div 0.44704 \approx 62.137\) mph. So 100 km/h is about 62.14 mph — a handy fact for reading speed limits abroad.
FAQ
Why is 1 mph = 0.44704 m/s? Because 1 mile = 1609.344 meters and 1 hour = 3600 seconds, so \(1609.344 \div 3600 = 0.44704\).
What is a knot? A knot is one nautical mile per hour, used in aviation and maritime navigation. One knot equals exactly 1.852 km/h, or about 0.51444 m/s.
Can I convert between the same unit? Yes — if "from" and "to" are identical, the value is returned unchanged.
