📏 Free Length Converter

What is this tool?

The Length Converter is a free online tool for converting distances and dimensions between metric and imperial units: millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles. Use it for DIY and construction measurements, travel distances, fabric and furniture dimensions, sports tracking, or schoolwork. It runs entirely in your browser, so your measurements never leave your device.

How it works

The tool uses the internationally defined conversion factors, with the meter as the base unit: 1 cm = 0.01 m, 1 in = 2.54 cm, 1 ft = 0.3048 m, 1 yd = 0.9144 m, 1 mi = 1609.344 m, and 1 km = 1000 m. Your input is converted to meters first and then to the target unit, which keeps every conversion exact regardless of the combination you choose.

How to use

1. Enter the length or distance value you want to convert.
2. Pick the input unit from the first dropdown (mm, cm, m, km, in, ft, yd, mi).
3. Pick the target unit from the second dropdown and click Convert.
4. Read your result instantly, with the conversion formula summarized below it.

Frequently Asked Questions

Which units does this converter support?

It supports millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles — the full set of everyday metric and imperial length units.

Is the length conversion exact?

Yes. The inch is officially defined as exactly 2.54 cm, and all other factors are derived from this definition, so results are exact.

Can it convert areas or volumes?

No, this tool converts one-dimensional length only. For surfaces use our Area Converter, and for capacity use our Volume Converter.

Tips & Advice

A quick mental reference: 1 inch ≈ 2.5 cm, 1 foot ≈ 30 cm, and 1 mile ≈ 1.6 km. When measuring for furniture or rooms, always measure in the same unit and convert once at the end to avoid small rounding errors.