Length Converter
Convert between metric and imperial units of length and distance instantly.
Convert length and distance units
This free length converter switches instantly between the units people use most — millimetres, centimetres, metres, and kilometres on the metric side, and inches, feet, yards, and miles on the imperial side, plus nautical miles for navigation. Just type a value, choose your units, and the answer updates as you type. Use the swap button to reverse the conversion.
Common length conversions
| From | To | Result |
|---|---|---|
| 1 inch | centimetres | 2.54 cm |
| 1 foot | metres | 0.3048 m |
| 1 metre | feet | 3.281 ft |
| 1 mile | kilometres | 1.609 km |
| 1 kilometre | miles | 0.621 mi |
| 1 yard | metres | 0.9144 m |
Metric vs imperial
Most of the world uses the metric system (millimetres, metres, kilometres), while the United States and, for some everyday uses, the United Kingdom still rely on imperial units (inches, feet, miles). This converter bridges the two, which is handy for travel, DIY projects, schoolwork, and international shopping. For area and volume conversions, see our other unit converters.
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54 centimetres. This is the internationally agreed definition of an inch.
How do I convert metres to feet?
Multiply the number of metres by 3.281. The converter above does this automatically — just select metres and feet.
How many feet are in a mile?
A mile is 5,280 feet, or 1,760 yards. In metric terms it is exactly 1,609.344 metres.
What is the difference between a mile and a nautical mile?
A nautical mile is 1,852 metres, about 15% longer than a standard (statute) mile. It is based on one minute of latitude, which makes it convenient for sea and air navigation. Speeds in nautical miles per hour are called knots; see the speed converter.
Exact length definitions
Since the international yard and pound agreement of 1959, every imperial length has been defined exactly in metric terms. That means the conversions below are not approximations; they are the legal definitions used in the UK, the US, Canada and Australia.
| Unit | Exact metric value | Imperial relationship |
|---|---|---|
| 1 inch | 25.4 mm | 1/12 of a foot |
| 1 foot | 304.8 mm (0.3048 m) | 12 inches |
| 1 yard | 914.4 mm (0.9144 m) | 3 feet |
| 1 mile | 1,609.344 m | 1,760 yards or 5,280 feet |
| 1 nautical mile | 1,852 m | about 6,076 feet |
Worked examples
Height in feet and inches to centimetres
Heights are often quoted in feet and inches, such as 5 ft 10 in. Convert to centimetres in two steps:
- Turn everything into inches: (5 × 12) + 10 = 70 inches.
- Multiply by 2.54: 70 × 2.54 = 177.8 cm.
Centimetres to feet and inches
Going the other way for 180 cm: 180 ÷ 2.54 = 70.87 inches. Divide by 12 to get feet: 70.87 ÷ 12 = 5 remainder 10.87, so 180 cm is about 5 ft 10.9 in.
Room dimensions for flooring or paint
A room measures 4.2 m by 3.6 m and a US product lists coverage in square feet. Convert each side first: 4.2 × 3.281 = 13.78 ft and 3.6 × 3.281 = 11.81 ft. The floor area is 13.78 × 11.81 = 162.7 sq ft. For area units directly, use the area converter, and for materials like gravel or concrete, the construction area calculator.
Running distances
A marathon is 42.195 km. Divide by 1.609344 to get miles: 42.195 ÷ 1.609344 = 26.22 miles. A 5K is 3.11 miles and a 10K is 6.21 miles. To convert pace as well as distance, try the athletic pace converter.
Quick mental shortcuts
- Kilometres to miles: multiply by 6 and divide by 10. 50 km is roughly 30 miles (exact 31.07).
- Miles to kilometres: multiply by 8 and divide by 5. 30 miles is about 48 km (exact 48.28).
- Metres to feet: multiply by 3 and add 10%. 10 m is about 33 ft (exact 32.81).
- Inches to centimetres: multiply by 2.5 for a quick estimate. 12 in is about 30 cm (exact 30.48).
Height conversion chart
| Feet and inches | Centimetres |
|---|---|
| 5 ft 0 in | 152.4 cm |
| 5 ft 3 in | 160.0 cm |
| 5 ft 6 in | 167.6 cm |
| 5 ft 8 in | 172.7 cm |
| 5 ft 10 in | 177.8 cm |
| 6 ft 0 in | 182.9 cm |
| 6 ft 2 in | 188.0 cm |
Where each unit is used
Science, engineering and most countries use the metric system throughout. The United States uses inches, feet, yards and miles for almost everything outside science. The UK uses metres for building and most official measures, but road signs give distances in miles and speeds in miles per hour, and many people still state their height in feet and inches. Aviation worldwide measures altitude in feet and distance in nautical miles, while shipping uses nautical miles and knots.
Need another conversion? Try the weight converter, the volume converter or the all-in-one unit converter.