Speed Converter: The Complete Guide
Convert speed instantly. Switch between km/h, mph, metres per second, knots, feet per second, and Mach, and see the conversion rate in both directions.
Who the Speed Converter is for
Drivers, runners, sailors, and aviators converting speeds between units.
How to use the Speed Converter
- Type your values into the fields above — pick your currency or units where the calculator offers them.
- Results update automatically as you type; there's no submit button and nothing is sent to a server.
- Adjust any input to compare scenarios, then copy the result with a single click.
How it works
Each unit has a fixed size in metres per second. The value is converted to m/s, then to the target unit: result = value × (from-unit m/s) ÷ (to-unit m/s).
Features
- km/h, mph, m/s, knots
- Mach (sea level)
- Two-way conversion rate
- Instant result
Speed units
Speed is distance over time, expressed in km/h or mph for vehicles, m/s in physics, and knots (nautical miles per hour) at sea and in the air. One knot is about 1.852 km/h. This converter also includes Mach (the speed of sound at sea level) for a sense of very high speeds.