Quick guide
How to use this calculator
- Enter the value exactly as recorded, then choose its source unit and the unit you need.
- Check regional and technical qualifiers in the unit names. US and Imperial gallons, force and mass, absolute temperatures and temperature differences, and decimal and binary data prefixes are deliberately separate.
- Use the selected result first, then open the common-equivalents table when you need to compare several standards without re-entering the value.
Calculation method
How the speed converter works
The entered speed is converted once to the canonical metre per second basis and then from that basis to the selected output unit.
Mach is shown using a fixed 340.29 m/s reference; actual speed of sound varies with atmospheric conditions.
Worked example
Speed example
100 km/h equals approximately 62.1371 mph.
source value × source-to-metre per second relationship → canonical metre per second value → destination-unit relationship
Supported inputs
Precision and limits
Unit convention
Mach is shown using a fixed 340.29 m/s reference; actual speed of sound varies with atmospheric conditions.
Precision
Definitions and exact conventional factors are retained internally where available. Display formatting uses up to 12 significant digits; very large or small results use scientific notation. Do not treat displayed digits as measurement accuracy beyond the source value.
Quantity boundary
This page converts speed. It does not infer a different physical quantity, material property, environmental condition, exchange rate, calendar rule, or regulatory value needed to make a cross-quantity conversion.
Privacy
Entered values and converted results stay in this browser and are not sent to analytics or third parties.
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