Units
Speed converter
Convert km/h, mph, and knots without treating Mach as a constant.
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What this tool does
A knot is one nautical mile per hour. Miles per hour use the international mile. ConvertPass will not invent a Mach number; that depends on local air temperature.
How to use it
- Enter the speed.
- Pick source and destination units.
- Convert and copy the JSON.
Supported input
- A number and two speed units from the menu
Output
- JSON with the converted speed plus every other unit in the family
Privacy
This tool processes files and text locally in your browser. Your content is not uploaded or stored by this site.
ConvertPass does not include your input in analytics, URLs, or error reports. Encoding: Decimal numbers / SI metre per second. Limit: A single speed (4.0 KB).
Limitations
- Mach, Beaufort, and indicated airspeed are not offered.
- Negative speeds are refused. This is a magnitude converter, not a velocity vector.
- Pace (min/km) is not in this family. Invert km/h yourself or use the time converter with distance.
Example
100 km/h → mph
{
"result": 62.1371192237,
"formatted": "100 km/h = 62.1371192237 mph"
}
Troubleshooting
- The aircraft log uses knots and I used mph
- Pick knot, not mile per hour. A knot is faster than a mph by the nautical-to-statute ratio.
FAQ
Why is Mach missing?
Mach 1 is not a fixed SI speed. It changes with temperature. ConvertPass will not pick 340.29 m/s and hide that.
Is a knot a nautical mile per hour?
Yes. 1852 m / 3600 s.
Can I convert a running pace?
Not as min/km. Convert km/h here, then invert if you want minutes per kilometre.
Does this know the speed limit?
No. It converts a number. It is not a legal speed database.
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Last reviewed 16 August 2026. Report a problem. Reports do not include your input.