How to use the length converter
- Type a number in the From box. Decimals (2.5) and thousands separators (1,250) both work.
- Pick the unit you have in the first menu and the unit you want in the second. The To box and the result line update as you type.
- To work backwards, type in the To box and the From box follows.
- Press Swap units to flip the direction, or read Same length in every unit to see your number in every other unit at once.
- For heights, use Feet and inches to centimeters: enter the feet and inches and read the answer in cm, m and total inches.
How the conversion works
Every unit is stored as a size in meters. The tool multiplies your number by the size of the From unit, then divides by the size of the To unit: result = value × From size ÷ To size. The inch, foot, yard and mile are the international units fixed by the 1959 yard and pound agreement. One inch is exactly 2.54 cm, which makes 1 ft = 0.3048 m, 1 yd = 0.9144 m and 1 mi = 1,609.344 m exact. A nautical mile is exactly 1,852 m, and a light-year is 9,460,730,472,580,800 m. The factors match NIST Guide to the SI, Appendix B.8. Answers show up to 8 significant digits.
Worked example with the default values
With 1 in the From box, Meter (m) as the From unit and Foot (ft) as the To unit, the result line reads 1 m = 3.2808399 ft, because 1 ÷ 0.3048 = 3.2808399. Under it you see the split 3 ft 3.37 in (0.2808399 × 12 inches) and the reverse line 1 ft = 0.3048 m. In the feet and inches card, 5 ft 10 in is 70 in, and 70 × 2.54 = 177.8 cm.
Common length conversions
| Convert | Result |
|---|---|
| 1 in | 2.54 cm |
| 1 ft | 30.48 cm |
| 1 yd | 0.9144 m |
| 100 m | 328.08399 ft |
| 1 mi | 1.609344 km |
| 5 km | 3.106856 mi |
| 10 km | 6.2137119 mi |
| 42.195 km | 26.218757 mi |
| 1 nmi | 1.852 km |
Training for a race? The kilometers to miles converter has a longer chart for runners and drivers. Measuring a room or a plot? Switch to the area converter for square feet and square meters, use the speed converter for mph and km/h, or try the unit converter for other kinds of unit.
Limits and edge cases
Negative numbers convert normally, which helps with depths and elevations below sea level. A comma followed by one or two digits counts as a decimal comma (1,5 is 1.5), while groups of three digits count as thousands (1,250 is 1250). Letters, currency symbols and slashes are blocked with a hint, and anything above 1e24 is refused. Tiny and huge answers appear as full digits in the boxes and in e-notation, such as 1.0570008e-25, in the result line. The foot is the international foot; the US survey foot, about 2 parts per million longer, is not included.
Sources: NIST Guide to the SI, Appendix B.8; NIST Handbook 44, Appendix C.
Length converter FAQ
How many feet are in a meter?
One meter is 3.2808399 feet, which is 3 feet 3.37 inches. Going the other way, one foot is exactly 0.3048 meters.
How do I convert feet and inches to centimeters?
Turn the feet into inches (feet times 12), add the remaining inches, then multiply the total by 2.54. For 5 ft 10 in that is 70 inches, and 70 × 2.54 = 177.8 cm. The feet and inches card on this page does the steps for you.
What is the difference between a nautical mile and a mile?
A statute mile is exactly 1,609.344 meters (5,280 feet). A nautical mile is exactly 1,852 meters, about 6,076 feet, and is used at sea and in aviation. One nautical mile is 1.1507794 statute miles.
How many miles is a 5K, a 10K and a marathon?
A 5K is 3.106856 miles, a 10K is 6.2137119 miles, and a marathon of 42.195 km is 26.218757 miles.