Speed Converter
Convert speed units instantly between km/h, mph, m/s, knots and feet per second. A precise tool for travel, sports, navigation, physics and everyday calculations.
Conversion result
The converted speed is displayed below.
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Understanding speed units
Speed is measured in different units depending on the context. Kilometers per hour (km/h) is used for road travel in most countries. Miles per hour (mph) is the standard in the United States and the United Kingdom. Meters per second (m/s) is the SI unit used in physics and science. Knots (kn) are used in maritime and aviation navigation: one knot equals one nautical mile per hour. Feet per second (ft/s) appears in some engineering and aerospace contexts.
Speed units by use case
Road transport relies on km/h or mph depending on the country. Aviation uses knots for airspeed and winds, and flight levels for altitude. Science and physics express speed in m/s as part of the SI system. Sports use a mix: athletics in m/s, cycling in km/h, sailing in knots.
When to use a speed converter?
- Understanding speed limits when driving abroad
- Converting wind speed from knots to km/h for weather reports
- Physics or engineering calculations requiring m/s from km/h or mph
Did you know?
The speed of sound at sea level is approximately 343 m/s, or about 1,235 km/h (767 mph). Breaking the sound barrier is called going supersonic, first achieved by Chuck Yeager in 1947.