Converters
Convert a length between common metric and imperial units.
Enter your numbers to see the answer.
Length converter guide
The length converter takes a single measurement in inches, feet, miles, centimeters, meters, or kilometers and expresses it in any of the others. Every conversion runs through the meter, the SI base unit of length, so no pair of units needs its own factor: the tool multiplies your value by the number of meters in the starting unit and divides by the number of meters in the destination. The imperial factors are exact by definition. Since the 1959 international agreement, 1 inch is exactly 25.4 mm, so 1 foot is exactly 0.3048 m and 1 mile is exactly 1,609.344 m. That means the result is limited only by the digits in your input, not by rounding in the factor. Use it for tape-measure readings, road distances, running routes, and product dimensions listed in a unit you do not think in. It handles length only; for areas and volumes, which scale by the square and cube of these factors, use the area and volume converters.
Length (to) = length (from) × meters per from-unit ÷ meters per to-unit. Factors (m): inch 0.0254, foot 0.3048, mile 1,609.344, centimeter 0.01, meter 1, kilometer 1,000.
Worked example with the defaults: 1 inch to centimeters. Step one converts to meters: 1 × 0.0254 = 0.0254 m. Step two divides by the meters in a centimeter: 0.0254 ÷ 0.01 = 2.54 cm, the figure the converter displays. The detail rows show the same length as 0.03 m (0.0254 rounded to two decimals) and 0.08 ft (1 ÷ 12 = 0.0833). To see the chain in the other direction, enter 100 centimeters to inches: 100 × 0.01 = 1 m, then 1 ÷ 0.0254 = 39.37 in.
Pick the starting unit in From and the destination in To; the value box takes a plain decimal in the From unit. Enter mixed feet-and-inches as a decimal first: 5 ft 10 in is 5 + 10 ÷ 12 = 5.8333 ft, or simply 70 in. Millimeters, yards, and nautical miles are not listed; enter millimeters as centimeters ÷ 10, yards as feet × 3, and nautical miles as 1.852 km each. Results round to two decimals, so tiny lengths such as 1 inch in meters (0.0254) show as 0.03.
Unit conversion is exact when the conversion factor is exact, so the only real uncertainty here is rounding and the precision of your input. Where a unit has more than one definition — US versus imperial measures, or short versus metric tons — the wrong variant produces a plausible-looking but wrong answer. The units note above states which definition this page uses. On this page the figure rests entirely on value, from and to, so start there if the length converter returns something you did not expect.
Good to know: the two-decimal display can hide precision on small results. 1 inch shows as 0.03 m, not 0.0254 m; convert to centimeters or millimeters instead when the small digits matter. Do not use the length factor for areas: a square foot is 0.3048² = 0.0929 m², not 0.3048 m². Survey feet also differ: the U.S. survey foot (1200 ÷ 3937 m) was deprecated at the end of 2022, and this tool uses the international foot of exactly 0.3048 m, which is 2 parts per million shorter.
Conversion results use stated mathematical factors and display precision. For regulated, medical, engineering, or contractual work, confirm the required standard and precision.
Sources
How it works
Convert a length between common metric and imperial units. This tool explains the calculation so you can adjust the assumptions to match your situation.
Worked example
With Value = 1 · From = inches · To = centimeters → 2.54 centimeters (1 inches converted to centimeters). Change an input above and this example updates with your numbers.
Common questions
Exactly 2.54 cm. The inch has been defined as 25.4 mm since the 1959 international yard and pound agreement, so 12 inches make a foot of exactly 30.48 cm and a yard is exactly 91.44 cm. Multiply inches by 2.54 for centimeters and divide centimeters by 2.54 for inches.
1 meter is 3.2808 feet, or 39.3701 inches, from 1 ÷ 0.3048. A quick check: 3 feet is 0.9144 m, so a meter is a yard plus about 3.37 inches. Ten meters is 32.81 ft, and 100 meters is 328.08 ft.
1 mile equals exactly 1.609344 km because a mile is 5,280 feet of 0.3048 m each. Going the other way, 1 km is 0.6214 miles. A 10 km race is 6.21 miles, and a marathon of 42.195 km is 26.22 miles.
5 ft 10 in is 70 inches, and 70 × 2.54 = 177.8 cm. Convert feet and inches to inches first (feet × 12 + inches), then multiply by 2.54. For 6 ft 2 in, that is 74 in × 2.54 = 187.96 cm.
No. It uses the international foot of exactly 0.3048 m, which is the definition NIST adopted for all purposes from 2023. The older survey foot is 0.3048006 m, longer by 2 parts per million, which only matters for large land surveys and state plane coordinates.