Convert kilometers per hour to miles per hour instantly, using the exact relationship where one mile per hour equals 1.609344 kilometers per hour. This is the conversion for making sense of metric speedometers, road signs, and speed limits when you are used to miles per hour, or for comparing car specs quoted in different systems. Type any speed in km/h and the mph value updates live as you type, carried to a couple of decimals for accuracy. People often approximate the factor as 1.6, which is close but off enough to matter at highway speeds, so the tool uses the exact value. Everything runs locally in your browser, which makes the result immediate, keeps your input private, and lets the converter keep working even when you are offline.