Conversion
Length Converter
Convert between metres, feet, inches, kilometres, miles, and more — instantly, in all units simultaneously.
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Formula: BIPM / NISTLast verified July 2026
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Quick reference — Feet conversions
| ft | mm | cm | m | km |
|---|---|---|---|---|
| 1 | 304.8 | 30.48 | 0.3048 | 3.0480e-4 |
| 5 | 1,524 | 152.4 | 1.524 | 0.001524 |
| 10 | 3,048 | 304.8 | 3.048 | 0.003048 |
| 25 | 7,620 | 762 | 7.62 | 0.00762 |
| 50 | 15,240 | 1,524 | 15.24 | 0.01524 |
| 100 | 30,480 | 3,048 | 30.48 | 0.03048 |
Worked Examples
5'10" height in centimetres
A person who is 5 feet 10 inches tall is 70 inches. Converting: 70 × 2.54 = 177.8 cm. Enter 70 in the inches field to confirm.
Marathon distance in miles and km
A marathon is exactly 42.195 km. That equals 26.2188 miles — rounded to the familiar 26.2 mi. The metric definition is exact by IAAF rules.
New York to Los Angeles in km
The driving distance is approximately 2,790 miles. That converts to 4,490 km, or 2,424 nautical miles — used in aviation routing.
Frequently Asked Questions
~4 min readHow many centimetres in an inch?▾
Exactly 2.54 centimetres. This is the international definition, adopted in 1959 by the US, UK, Canada, Australia, and South Africa. All inch/cm conversions follow from this single exact value.
What is the difference between a mile and a nautical mile?▾
A statute mile (the everyday mile) is 1,609.344 metres. A nautical mile is 1,852 metres — defined as one arc-minute of latitude. Nautical miles are used in aviation and maritime navigation because they map directly onto geographic coordinates.
How many metres in a foot?▾
Exactly 0.3048 metres. This follows from the 1959 international inch definition. So 1 yard = 3 feet = 0.9144 m, and 1 mile = 5,280 feet = 1,609.344 m.
Is kilometre or kilometer correct?▾
Both spellings are correct. "Kilometre" is standard in British English (and most countries); "kilometer" is the US spelling. The SI official spelling is "kilometre".
What is the shortest unit you support?▾
Millimetres (mm). 1 mm = 0.001 m. For scientific work requiring micrometres or nanometres, multiply the mm result by 1,000 or 1,000,000 respectively.
Why does aviation use feet for altitude?▾
ICAO (the International Civil Aviation Organisation) standardised on feet for altitude reporting in the 1940s when most aircraft were US-built. Despite global metrication, feet remain the standard above the transition altitude — changing would require simultaneous retraining of all pilots and ATC worldwide.