Length Converter
Convert length measurements instantly with this free length converter. Works with millimeters, centimeters, meters, kilometers, inches, feet, yards and miles.
About this tool
Length comes up everywhere: measuring a room before buying furniture, checking luggage size limits, reading a sewing pattern or converting a race distance. Metric and imperial units collide constantly, and a wrong conversion can mean a shelf that does not fit through the door.
Our free length converter handles all eight common units, from millimeters to miles. Enter your measurement, choose the units, and get an exact conversion instantly, plus the value in meters as a handy reference.
How to use
Type the measurement into the value field, select the unit you are converting from and the unit you want, then press Convert. The main result appears first, followed by the equivalent in meters so you can sanity-check the scale.
Everything runs in your browser with no sign-up. Convert as many measurements as you need, one after another.
The math behind it
The converter uses meters as its internal base. Each unit is defined exactly in meters: an inch is 0.0254 m, a foot is 0.3048 m, a yard is 0.9144 m and a mile is 1609.344 m. Your value is first turned into meters, then divided by the target unit's factor.
Because these are exact international definitions, the math is precise to the last decimal. Only the display is rounded for readability.