How to use the length converter
Type a length in the Value box, choose the unit you are starting from and the unit you want, then press Convert. The swap button between the two lists flips the direction, which is handy when you want to check a result backwards.
Below the main answer you also get a table with the same length expressed in all nine supported units, so you rarely need to convert twice.
How the conversion works
Every unit is defined as an exact multiple of the meter, and the converter goes through that common base:
- 1 inch = 2.54 cm exactly
- 1 foot = 12 inches = 0.3048 m
- 1 yard = 3 feet = 0.9144 m
- 1 mile = 5,280 feet = 1,609.344 m
- 1 nautical mile = 1,852 m
Result = Value × (meters per source unit) / (meters per target unit).
Worked example
To turn 5 miles into kilometers: 5 × 1,609.344 m = 8,046.72 m, and 8,046.72 / 1,000 = 8.04672 km.
Good to know
- Results are shown with up to six decimal places. Very small values are written in scientific notation, for example 6.21371e-7 means 0.000000621371.
- Lengths cannot be negative, so a minus sign is rejected. Zero is accepted.
- The nautical mile is used at sea and in aviation. It is about 15% longer than a regular (statute) mile.
- Because the inch has been defined as exactly 2.54 cm since 1959, conversions between metric and imperial units here are exact, apart from the final rounding for display.