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About Length Converter Online

This tool converts between length and distance units: meters, kilometers, miles, yards, feet, inches, centimeters, millimeters, micrometers, nanometers, nautical miles, and light-years.

Length conversions are one of the most frequently needed unit conversions. Common scenarios include converting building measurements between metric and imperial, calculating running distances, comparing screen sizes in different markets, and scientific calculations requiring SI prefixes.

All conversions use precise international standards, including the exact definition of the inch as 25.4 mm and the nautical mile as 1852 m.

How to use this tool

How to convert lengths

  1. Enter the length value

    Type the number you want to convert in the Value field. Decimals are fine — use a dot, not a comma (e.g. 1.75).

  2. Pick the source unit

    From offers m, km, cm, mm, mi, yd, ft, and in. Pick the unit your number is already in.

  3. Pick the target unit

    To lists the same units. Mix metric (m/km/cm/mm) and imperial (mi/yd/ft/in) freely — e.g. ft → cm or mi → km.

  4. Press Run and copy

    Result is computed to 12 significant digits via metres as the bridge unit. Copy the figure, then round per your spec if needed.