Speed Converter
Convert meters per second, kilometers per hour, miles per hour, feet per second, knots, Mach and light speed. Covers road travel, sports, marine/aviation and physics — instant real-time results.
Speed conversion
Speed Convert
All units overview
All Units Overview
Speed Converter Guide
m/s / km/h / mph / knots / Mach / light speed
The speed converter covers seven units spanning daily travel, marine/aviation and physics education: meters per second, kilometers per hour, miles per hour, feet per second, knots (nautical miles per hour), Mach and the speed of light. It is useful for road travel, sports tracking, sailing and flying, physics learning and engineering calculations. Enter any speed value to instantly convert all units, helping you switch between speed limits, sports data and scientific constants in different countries.
Speed converter guide
Speed conversion is used in driving, sports, marine/aviation and physics. This tool covers 7 units from everyday km/h to the extreme speed of light; enter any value and see all units at once.
Everyday speed: km/h, mph, m/s
km/h is the road standard in China and most countries; 1 m/s = 3.6 km/h. mph is used in the US and UK; 1 mph ≈ 1.609 km/h.
Marine/aviation: knots
1 knot (kn) = 1 nautical mile/hour = 1.852 km/h, the standard unit in sailing and aviation, not used on land.
Extreme: Mach and light speed
Mach is based on the speed of sound (≈ 340.29 m/s at sea level, 20°C) and varies with altitude/temperature; light speed c ≈ 299,792,458 m/s is the cosmic speed limit.
FAQ
QHow many km/h in 1 m/s?
1 m/s = 3.6 km/h, the most common speed conversion.
QWhat is 100 km/h in mph?
100 km/h ÷ 1.609 ≈ 62.14 mph.
QWhat is a knot?
1 knot = 1 nautical mile/hour ≈ 1.852 km/h ≈ 0.514 m/s, used in marine and aviation.
QHow fast is Mach 1?
Mach 1 ≈ 340.29 m/s ≈ 1225 km/h at sea level (20°C); it is lower (~295 m/s) at high altitude.
QWhat is the speed of light?
In a vacuum c ≈ 299,792,458 m/s ≈ 1.079 billion km/h, the cosmic speed limit.