About the length converter
Metric and imperial distances: mm, cm, m, km, inches, feet, yards, miles. Pick any two units and the result updates as you type; the exact conversion factor (or formula) is shown beneath the result so you can check it by hand.
How the math works
Linear units convert by one multiplication: the value is scaled by the ratio of the two units' definitions. Factors here follow the SI and NIST SP 81 definitions.
Worked example
- Enter the value you have (default 1)
- Choose the unit you have in From
- Choose the unit you want in To
- Read the result and the factor line beneath the board
How to use it
- Type a value
- Pick the two units
- Read the converted result with its exact factor