Length Converter
Convert between meters, feet, inches, km, miles, cm, mm, yards, and more length units instantly.
About this calculator
Pick a unit to convert from, a unit to convert to and type a value. The Length Converter returns the answer instantly and also lists your value in every other length unit, from millimetres and inches to nautical miles and light years.
It is built for the tasks people actually have: turning a height from feet to centimetres, a run from miles to kilometres, a screen size from inches to millimetres, or a flight leg from nautical miles to kilometres. Factors are the exact international ones, not rounded approximations.
How to use it
- Type the Value.
- Choose the unit in From and the unit in To.
- Read the result, and use the table underneath to see the value in all other units. The ⇄ button swaps the units.
Factors and method
Conversions go through metres. 1 inch = 2.54 cm exactly, 1 foot = 0.3048 m exactly, 1 yard = 0.9144 m, 1 mile = 1,609.344 m and 1 nautical mile = 1,852 m. To convert, multiply by the factor of the starting unit and divide by the factor of the target unit: value × from ÷ to.
Worked example
Everyday conversions
| 5 ft 10 in (70 inches) | 177.8 cm |
| 10 km | 6.2137 miles |
| 100 m (sprint) | 328.084 feet |
| Marathon, 42.195 km | 26.2188 miles |
| 1 mile | 1.609344 km |
Going the other way, 1 km is 0.621371 miles and 1 m is 39.3701 inches.
Tips and common mistakes
- Remember 1 inch = 2.54 cm exactly. Many other factors derive from it.
- For heights, convert feet and inches to total inches first, then multiply by 2.54.
- Do not confuse a statute mile (1.609 km) with a nautical mile (1.852 km).
- Keep extra decimals during multi-step calculations and round at the end.
- Check the unit list twice. Millimetre and micrometre are easy to mix up on small values.
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54 centimetres.
How many feet are in a metre?
About 3.28084 feet.
How many kilometres are in a mile?
1.609344 kilometres.
What is a nautical mile?
1,852 metres, used at sea and in aviation. It equals one minute of latitude.
What is a light year?
The distance light travels in a year, about 9.46 trillion kilometres.
How do I convert feet and inches to centimetres?
Multiply feet by 30.48 and inches by 2.54, then add the two results.