Length Converter
Convert between metric lengths (millimeters to kilometers) and the international units used in the US and UK (inches, feet, yards, miles). Every unit is defined exactly in meters, so results are exact before rounding.
Formula: multiply the source value by 0.62137119
Quick Conversions
About this tool
Every length unit is expressed in meters first, then scaled to the unit you need. The meter is the SI base unit for length.
How to use it
Choose a source unit, enter a value, then pick the target unit. Conversion updates as you type. Use swap to reverse the pair.
value_to = value_from × (from_in_meters / to_in_meters)
Examples
10 km to miles
10 × 0.621371 = 6.21371 mi.
1.75 m to ft
1.75 × 3.28084 = 5.74147 ft.
26.2 mi to km
26.2 × 1.60934 = 42.1648 km.
Every unit expressed in meters
| Unit | Equal to (m) |
|---|---|
| 1 meter (m) | 1 |
| 1 kilometer (km) | 1,000 |
| 1 centimeter (cm) | 0.01 |
| 1 millimeter (mm) | 0.001 |
| 1 mile (mi) | 1,609.344 |
| 1 yard (yd) | 0.9144 |
| 1 foot (ft) | 0.3048 |
| 1 inch (in) | 0.0254 |
FAQ
How many centimeters are in an inch?
Exactly 2.54 cm. That constant underpins the imperial conversions here.
Can I convert negative lengths?
No. Length is a magnitude, so negative values are rejected.
Is the conversion exact?
Yes, before rounding. Both units are defined exactly in meters, so the only difference comes from how many decimals you choose to display.