Length converter
Convert length between m, km, cm, mm, in, ft, yd and mi using exact international factors. Example: 5 mi is 8.04672 km; 1 in is 2.54 cm.
What to know
The length page offers eight units: metre, kilometre, centimetre, millimetre, inch, foot, yard and mile. Every value goes through metres, using exact legal factors: 1 in = 0.0254 m, 1 ft = 0.3048 m, 1 yd = 0.9144 m and 1 mi = 1,609.344 m.
Worked example: 5 mi to km is 5 x 1609.344 / 1000 = 8.04672 km. In the other direction, 100 m to ft is 100 / 0.3048 = 328.08399 ft, and a marathon of 42,195 m reads 26.218757 mi.
These factors describe the international inch, foot, yard and mile. They do not cover the US survey foot, nautical miles or old regional units, which differ by a few parts per million or more.
The default pair is m to km, so you can convert a distance in one click. Typical jobs include reading a road sign abroad, translating a screen size in inches into centimetres, or checking a plank length against a catalogue in feet.
For woodworking and construction, remember that 1 yd is exactly 3 ft and 1 ft is exactly 12 in. Converting 6 ft 2 in therefore needs two steps: 6 ft is 1.8288 m and 2 in is 0.0508 m, which add up to 1.8796 m.
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How to use Length converter
- Type 5 in the Value field.
- Pick mi in From and km in To.
- Read the Result line, which shows 8.04672 km.
- Press Swap units to convert in the other direction, or set To to ft for 26,400 ft.
Quick answers
How many centimetres are in an inch?
Exactly 2.54, because the international inch is defined as 0.0254 m. Choose in then cm and enter 1.
How many feet are in a kilometre?
3,280.839895 ft, from 1000 / 0.3048. The result is rounded to 6 decimals.
Are nautical miles available?
No. Only statute miles (1,609.344 m) are offered, which matters for sea and air distances.