Length Converter (m, ft, in, cm, km, mi)
Metres to feet, centimetres to inches, kilometres to miles, instantly and exactly.
Free forever, no sign-up and no limits, and this tool installs on its own so you can keep it on your home screen.
Convert between metres, feet, inches, centimetres, kilometres, miles and nautical miles instantly. Type into either box and the other updates, and the exact factor used appears beneath the result so you can check it. Free, instant, and nothing to install.
How to use it
- Enter a valueType your number into either box. Conversion works in both directions, so you can start from whichever number you already have.
- Choose the unitsPick from the two dropdowns, or press Swap units to reverse the conversion.
- Check the factorThe line beneath the result shows the exact factor applied, for example 1 m = 3.2808399 ft.
Popular conversions
Jump straight to the pair you need, each opens preset, with its own quick table:
Exact by definition
Nearly every conversion on this page is exact rather than approximate. In 1959 the United States, United Kingdom, Canada, Australia, New Zealand and South Africa agreed to define the inch as exactly 25.4 millimetres. Everything imperial follows from that one number: a foot is twelve inches, a yard is three feet, a mile is 5,280 feet.
Because those relationships are definitions, a converter has no excuse for using a rounded factor. This one stores the full value and rounds only the number it displays. Chain a few conversions together (metres to feet to inches and back) and you will land exactly where you started.
Common conversions
- 1 inch = 2.54 cm (exact)
- 1 foot = 0.3048 m (exact)
- 1 yard = 0.9144 m (exact)
- 1 mile = 1.609344 km (exact)
- 1 metre = 3.2808399 ft
- 1 nautical mile = 1,852 m (exact)
Where each unit is used
The metre is the base unit of length in the International System and is standard almost everywhere for science, engineering and trade. Feet and inches remain in general use in the United States, and survive in the UK for height, and in aviation worldwide, cruising altitudes are quoted in feet regardless of the country. Height is the classic compound case, so the tool takes feet and inches as a pair: type 5 ft 10 in and it converts as 70 inches, and any answer in feet is also read back as feet and inches. A workshop line gives the nearest sixteenth of an inch, the resolution of most tape measures.
Nautical miles and knots belong to sea and air navigation, for a reason worth knowing: one nautical mile is roughly one minute of latitude, so a navigator can read distance directly off a chart's latitude scale.
Limitations
This converter handles length only. It will not convert length to area or volume, those are squared and cubed relationships, so a separate tool applies the factor the right number of times. It also assumes the international foot; if you are working with pre-2023 US land survey records, those used a very slightly different foot.
Questions people ask
How many feet is one metre?
One metre is approximately 3.2808399 feet. The relationship is defined in the other direction: one foot is exactly 0.3048 metres, which follows from the 1959 international agreement fixing the inch at exactly 25.4 millimetres.
How many centimetres is an inch?
Exactly 2.54 centimetres. This is a definition rather than a measurement, so it carries no rounding error at all.
How many kilometres is a mile?
Exactly 1.609344 kilometres. A mile is 5,280 feet, each foot exactly 0.3048 metres, so the result is exact by definition.
What is a nautical mile and why is it different?
A nautical mile is exactly 1,852 metres, fixed by international agreement in 1929. It was originally defined as one minute of latitude along a meridian, which is what makes it useful for sea and air navigation. It is about 15% longer than a statute mile, so never substitute one for the other.
Are US and UK feet and inches the same?
Yes for all everyday purposes. Both adopted the international foot of exactly 0.3048 metres in 1959. The United States kept a separate survey foot for land surveying, larger by about two parts per million, but it was officially retired at the end of 2022.
Why does the result show fewer decimals than I expected?
Only the display is shortened, to keep everyday answers readable. The calculation runs at full double precision, so converting back and forth returns your original number.
How do I convert feet and inches to centimetres?
Turn the whole thing into inches first, then multiply by 2.54. A height of 5 ft 10 in is 70 inches, so 177.8 cm. The converter takes feet and inches as a pair, so you can type both and skip the adding up.