Speed Converter
Convert speeds between km/h, mph, m/s, ft/s, knots and Mach. Results update as you type, and a full table shows the value in every supported unit at once.
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What does the Speed Converter do?
Speed limits, weather reports, aviation and science use different units. The converter uses exact relationships (1 mph = 0.44704 m/s, 1 knot = 1,852 m per hour) and includes Mach 1 at sea-level conditions (about 343 m/s), labelled as an approximation because the speed of sound changes with temperature and altitude.
How to use the Speed Converter
- Enter a speed.
- Choose the units.
- Read the result and table.
Examples
Motorway
120 km/h ≈ 74.56 mph.
Wind
20 knots ≈ 37.04 km/h.
Common use cases
- Driving and travel abroad
- Weather and wind speed
- Aviation and sailing
- Physics problems
Features and benefits
- Private by design — your data is processed on your device and never uploaded.
- Free with no account, no watermark and no usage limits.
- Works on phones, tablets and desktops in any modern browser.
Limitations to know
- Mach is approximate (sea level, 15 °C).
Frequently asked questions
How do I convert km/h to m/s?
Divide by 3.6.
What is a knot?
One nautical mile per hour, about 1.852 km/h.
Is Mach a fixed speed?
No, it depends on air temperature; 343 m/s is a sea-level approximation.
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