Length Converter
Metres, feet, miles, inches and more in one place.
Reviewed by the Calculation Machine team · Updated 24 October 2026 · How we check our maths
Your values
ⓘ Live results
- Metres
- 100
- Feet
- 328.08399
- Inches
- 3937.0079
- Miles
- 0.06213712
- Feet and inches
- 328' 1"
| Unit | Value |
|---|---|
| mm | 100000 |
| cm | 10000 |
| m | 100 |
| km | 0.1 |
| in | 3937.007874 |
| ft | 328.08399 |
| yd | 109.36133 |
| mi | 0.062137 |
| nmi | 0.053996 |
Quick answer
Every metric–imperial length conversion rests on one exact definition: 1 inch = 2.54 cm. From it, 1 foot = 30.48 cm, 1 yard = 0.9144 m and 1 mile = 1.609344 km, all exact. A nautical mile is defined separately as exactly 1,852 m. So 100 meters is 328.08 feet, and 6 feet is 1.8288 m.
What the Length Converter does
This converter changes a length from any of nine units — millimeters, centimeters, meters, kilometers, inches, feet, yards, miles and nautical miles — into all the others at once, and also gives the answer in feet and inches. It covers everyday jobs such as converting a height, a room dimension, a race distance or a sailing route.
The imperial units here are the international yard and foot used in the US, UK, Canada and Australia since 1959. They are defined in metric terms, so conversions are exact, and any difference you see in the last decimal place comes from rounding for display.
For surfaces rather than distances, use the area converter; squaring a length factor is a common source of error, covered below. To convert pace or travel rates, the speed converter uses the same mile and kilometer definitions.
The formula
Length in target unit = length × (meters per source unit) ÷ (meters per target unit)
| Symbol | Meaning | Unit |
|---|---|---|
| 1 in | 0.0254 m exactly | m |
| 1 ft | 12 in = 0.3048 m exactly | m |
| 1 yd | 3 ft = 0.9144 m exactly | m |
| 1 mi | 5,280 ft = 1,609.344 m exactly | m |
| 1 nmi | International nautical mile = 1,852 m exactly | m |
The inch, foot, yard and mile are fixed by the 1959 international yard and pound agreement; the nautical mile by the International Hydrographic Conference of 1929. NIST retired the slightly different US survey foot at the end of 2022, so the international foot is now the single US foot for new work. The meter itself is defined through the speed of light in the SI.
Worked examples
Height in centimeters to feet and inches
A height of 175 cm on a European form that needs converting for a US one.
Inputs
- Value175
- FromCentimetres
Result
- Metres1.75
- Feet5.74147
- Inches68.8976
- Miles0.0010874
- Feet and inches5' 8.9"
175 cm is 5 ft 8.9 in, usually written as 5′9″ when rounded to the nearest inch. Divide centimeters by 2.54 for total inches, then by 12 for feet.
Marathon distance
Converting the commonly quoted 26.2-mile marathon into meters.
Inputs
- Value26.2
- FromMiles
Result
- Metres42164.8128
- Feet138336
- Inches1660032
- Miles26.2
- Feet and inches138336' 0"
26.2 miles is about 42,165 m. The official marathon is 42.195 km, which is 26.219 miles, so "26.2" is a rounded figure about 30 m short.
Nautical miles for sailing
A 10-nautical-mile passage being compared with road distances.
Inputs
- Value10
- FromNautical miles
Result
- Metres18520
- Feet60761.154856
- Inches729133.8583
- Miles11.50779448
- Feet and inches60761' 1.9"
10 nautical miles is 18.52 km or about 11.5 statute miles. A boat making 6 knots covers it in about 1 hour 40 minutes, since a knot is one nautical mile per hour.
Length conversion factors
Exact values are shown in full; others are rounded.
| Unit | Meters | Feet | Common use |
|---|---|---|---|
| 1 millimeter | 0.001 | 0.00328 | Engineering drawings, rainfall |
| 1 centimeter | 0.01 | 0.0328 | Body measurements, small objects |
| 1 inch | 0.0254 (exact) | 0.0833 | Screens, lumber, US measurements |
| 1 foot | 0.3048 (exact) | 1 | Height, rooms, altitude in aviation |
| 1 yard | 0.9144 (exact) | 3 | Fabric, US and UK sports fields |
| 1 meter | 1 | 3.28084 | Metric standard |
| 1 kilometer | 1,000 | 3,280.84 | Road distances outside the US and UK |
| 1 mile | 1,609.344 (exact) | 5,280 | US and UK road distances |
| 1 nautical mile | 1,852 (exact) | 6,076.12 | Sea and air navigation |
Quick mental conversions
- Inches to cm: multiply by 2.5 for a quick estimate (2.54 exactly).
- Feet to meters: divide by 3.3; 10 ft ≈ 3 m.
- Meters to feet: multiply by 3.3; a 100 m sprint is about 328 ft.
- Miles to km: multiply by 1.6, or use Fibonacci numbers — 5 mi ≈ 8 km, 8 mi ≈ 13 km.
- Km to miles: multiply by 0.62; a 5K run is 3.1 miles and a 10K is 6.2 miles.
For a walking or running distance counted in steps, the steps to distance calculator converts stride count into miles or kilometers.
Converting area and volume is different
A length factor applies once per dimension. One meter is 3.28084 feet, so one square meter is 3.28084² = 10.764 square feet, and one cubic meter is 3.28084³ = 35.315 cubic feet. Using the plain length factor for an area or volume underestimates it badly — 10 m² is 107.6 sq ft, not 32.8. Convert the individual dimensions first and then multiply, or use a dedicated area or volume converter.
How to use the Length Converter
- 1Enter the length. For feet and inches, convert to decimal feet first (5 ft 6 in = 5.5 ft) or enter total inches.
- 2Choose the unit you are converting from.
- 3Read the result in every unit, including the feet-and-inches form for heights and room sizes.
- 4Round the result to a sensible precision — a few millimeters or a sixteenth of an inch for building work.
Frequently asked questions
How many centimeters are in an inch?
Exactly 2.54 centimeters. This has been the legal definition of the inch since 1959.
How many feet are in a meter?
About 3.28084 feet, or 3 feet 3.37 inches. One foot is exactly 0.3048 meters.
How many kilometers are in a mile?
Exactly 1.609344 kilometers. One kilometer is about 0.6214 miles.
What is the difference between a mile and a nautical mile?
A statute mile is 5,280 feet (1,609.344 m); a nautical mile is 1,852 m, about 1.15 statute miles. Nautical miles are used at sea and in aviation because one nautical mile is close to one minute of latitude.
How do I convert cm to feet and inches?
Divide by 2.54 to get inches, then divide by 12: the whole number is feet and the remainder is inches. 180 cm = 70.87 in = 5 ft 10.9 in.
References
- NIST Handbook 44, Appendix C: General Tables of Units of Measurement — National Institute of Standards and Technology
- The International System of Units (SI Brochure) — Bureau International des Poids et Mesures (BIPM)
- Weights and Measures Act 1985 — UK Parliament (legislation.gov.uk)
About this calculator
- Built and reviewed by the Calculation Machine team · How we build and test calculators
- Last reviewed: October 24, 2026
- Report an error