Convert a length or distance
- Enter a nonnegative decimal value and choose its unit.
- Choose the target unit and convert.
- Review the target value, metre equivalent and multiplier; copy or download the result.
Definitions and examples
One international mile is 1.609344 kilometres; one inch is 2.54 centimetres; one foot is 12 inches. Decimal feet are a decimal quantity: 5.5 feet means 5 feet 6 inches. Entering 5.6 feet means 5 feet 7.2 inches.
The calculation is value × source factor in metres ÷ target factor in metres. International definitions follow NIST’s unit tables, Appendix E. These definitions are exact; browser floating-point arithmetic and displayed rounding have finite precision.
| Unit | Metres per unit |
|---|---|
| Nanometres (nm) | 1e-9 |
| Micrometres (µm) | 0.000001 |
| Millimetres (mm) | 0.001 |
| Centimetres (cm) | 0.01 |
| Metres (m) | 1 |
| Kilometres (km) | 1000 |
| Inches (in) | 0.0254 |
| Feet (ft) | 0.3048 |
| Yards (yd) | 0.9144 |
| Miles (mi) | 1609.344 |
| Nautical miles (nmi) | 1852 |
Limits and privacy
Nonnegative values up to 10¹⁵ in the chosen source unit. Extremely tiny values that underflow arithmetic are rejected. Uses international foot, yard and mile; historical US survey feet, astronomical distances are not supported. Mixed feet/inches use separate fields with whole feet and inches from zero to less than 12. This converts length, not area or volume.
Results show up to 12 significant digits and six decimal places, with scientific notation for very small or large values. CSV retains JavaScript’s numeric result, which can include floating-point rounding; it is not an arbitrary-precision measurement certificate. Inputs stay in browser memory, with no upload or saved measurements. Live conversion waits 300 ms after editing. Swap units keeps the numeric value; Use result as next input swaps direction while retaining the quantity and unrounded numeric result. Swap, examples, Reset and result reuse offer one undo step. Typing discards that action history. Reset clears results and restores one mile to kilometres. The all-units table and CSV compare every supported unit for the current quantity; an empty CSV value indicates numeric underflow/overflow for that comparison.
Are a mile and a nautical mile the same?
No. An international mile is 1609.344 metres; an international nautical mile is 1852 metres. Select the unit that your measurement actually uses.