Speed converter
Convert km/h, m/s, mph, knots and feet per second.
How the calculation works
Speed is distance over time. The conversion takes everything to meters per second (m/s), then to the target unit.
Most useful conversions
- km/h → m/s: divide by 3.6 (72 km/h = 20 m/s)
- m/s → km/h: multiply by 3.6
- 1 mph = 1.609 km/h · 1 knot = 1.852 km/h
Step-by-step example
100 km/h in m/s: 100 ÷ 3.6 = 27.8 m/s. In mph: 62.1 mph.
Why divide by 3.6
Because 1 km = 1,000 m and 1 h = 3,600 s, so km/h × (1000/3600) = km/h ÷ 3.6.
Examples
- 60 km/h = 16.67 m/s (60 ÷ 3.6).
- 30 mph = 48.3 km/h (30 × 1.609).
Frequently asked questions
Quick km/h to m/s?
Divide by 3.6. For the reverse, multiply by 3.6.
What is a knot?
One nautical mile per hour (1.852 km/h), used at sea and in aviation.
How much is 1 mach?
The speed of sound, ~1,235 km/h at sea level (it varies with temperature and altitude).
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Updated on June 17, 2026 · by Rafael Rossi · Methodology & sources