Length Converter
Convert between length units — meters, kilometers, centimeters, millimeters, miles and more.
Reviewed by the ToolNestr Editorial Team — July 2026
About this length converter
Length measures distance, from the thickness of a wire to the span of a journey. This length converter lets you move between 9 different length units in either direction. Pick the unit you are starting from, the unit you want, and enter a value — the result appears instantly as you type, with the calculation running entirely in your browser.
Internally, every unit is defined by its exact ratio to a single base unit, the meter. To convert, the tool first changes your value into the base unit, then into the target unit. This base-unit method keeps results consistent and precise no matter which pair of units you choose, and makes it easy to add uncommon units alongside the everyday ones.
Use the swap control to reverse the direction at any time, which is handy when you are checking a figure both ways. Because the converter is mobile-first and works offline once loaded, it is a quick reference for length whether you are studying, working, travelling or shopping across measurement systems.
Supported length units
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Frequently asked questions
How does this length converter work?
Choose the unit you have and the unit you want, type a value, and the tool converts it via a common base unit (the meter). It supports 9 length units.
Is the length converter accurate?
Yes. Every unit is defined by its exact ratio to the meter, so conversions are precise; displayed results are rounded for readability.
Can I convert in both directions?
Yes. Swap the “from” and “to” units, or press the swap button, to convert either way between any two length units.
Which length units are supported?
It includes Meters, Kilometers, Centimeters, Millimeters, Miles, Yards, Feet, Inches, Nautical miles.