What this calculator does
This general-purpose conversion calculator converts a length value between eight common units: millimeters, centimeters, meters, kilometers, inches, feet, yards, and miles.
How the calculation works
The calculator first converts your input into meters using each unit’s standard, internationally-defined conversion factor (for example, 1 inch equals exactly 0.0254 meters), then converts that meter value into your chosen output unit.
This tool is intended for general everyday, educational, and reference use.
Last reviewed August 2026