Speed conversions are simple arithmetic on top of distance, because an hour is an hour everywhere. What varies is the distance unit, and one of them is unusual: the knot is a nautical mile per hour, and the nautical mile was fixed at exactly 1852 metres to approximate one minute of latitude. That is why it converts to a round metric figure while the statute mile does not, and why navigation still uses it.
Tools in this category
Feet per Second to Meters per Second
Convert feet per second to meters per second in your browser. A foot is exactly 0.3048 meters, so the factor is exact.
Meters per Second to Kilometers per Hour
Convert meters per second to kilometers per hour in your browser. Multiply by 3.6 — both units are metric.
Knots to Kilometers per Hour
Convert knots to kilometers per hour in your browser. A knot is one nautical mile an hour — exactly 1.852 km/h.
Miles per Hour to Kilometers per Hour
Convert miles per hour to kilometers per hour in your browser. The factor is the same exact 1.609344 as for distance.
km/h to mph
Convert kilometers per hour to miles per hour. The ratio is the exact 1.609344 that relates the distance units, because an hour is an hour on both sides.
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How these tools are built
Every tool in this category runs entirely in your browser: there is no upload, no account and no request to a server once the page has loaded. The numbers behind them are transcribed from the organisation that defines them — NIST for units, the W3C for web formats, the WHO for health measures — and each page names its source next to the formula. A tool whose reference values stop reproducing fails the build and does not ship, which is the whole reason the catalogue grows slowly.