Convert 11 kinds of units with exact factors, from feet to metres to GiB.
0.3048 m
Exact
1 ft = 0.3048 m
| Unit | Value |
|---|---|
| Nanometre (nm) | 304,800,000 nm |
| Micrometre (µm) | 304,800 µm |
| Millimetre (mm) | 304.8 mm |
| Centimetre (cm) | 30.48 cm |
| Metre (m) | 0.3048 m |
| Kilometre (km) | 0.0003048 km |
| Inch (in) | 12 in |
| Foot (ft) | 1 ft |
| Yard (yd) | 0.3333333333 yd |
| Mile (mi) | 0.0001893939394 mi |
| Nautical mile (nmi) | 0.0001645788337 nmi |
It converts a value between units of the same quantity: length, mass and weight, temperature, area, volume, speed, data size, time, energy, pressure and fuel economy. Choose the quantity, type a value, pick the unit you have and the unit you want, and the result appears as you type, together with a line such as "1 ft = 0.3048 m" and a table with the same value in every unit of that quantity. Swap the two units with one click and copy the result with its unit symbol.
Every unit is stored as an exact fraction of a base unit, taken from the definitions that fix it. The inch has been exactly 0.0254 metres since 1959, so a foot is 0.3048 m and a mile is 1,609.344 m. The pound is exactly 0.45359237 kg. A US gallon is 231 cubic inches, which makes it exactly 3.785411784 litres, and an imperial gallon is exactly 4.54609 litres. Because the arithmetic is done with whole-number fractions rather than floating point, converting miles to feet gives exactly 5,280 and converting a value there and back gives back the value you typed. The only rounding happens once, at the end, to the number of significant digits you chose, and the tool tells you when that rounding changed anything.
A few units have no exact definition of their own, and the tool uses the conventional value: the British thermal unit (1,055.05585262 J, the international table value), the millimetre of mercury (133.322387415 Pa) and the inch of mercury (3,386.389 Pa). The average month and year follow the Gregorian calendar: 365.2425 days in a year and a twelfth of that in a month.
For money, use the currency converter; for percentages, the percentage calculator; and for formulas with powers and roots, the scientific calculator.
Exactly 0.3048 metres. Since 1959 the inch is defined as 0.0254 m, so a foot (12 inches) is exactly 0.3048 m and a mile (5,280 feet) is exactly 1,609.344 m.
The drive is sold in decimal terabytes (10^12 bytes), and the computer counts in binary units of 2^30 bytes while still writing GB. 10^12 bytes is 931.32 GiB. No space is lost.
Divide 235.215 by the L/100 km figure for US mpg, or 282.481 for UK mpg. Choose Fuel economy here for the exact value: 5 L/100 km is 47.04 US mpg.
Yes, which matters for temperatures: −40 °C is −40 °F. The tool refuses anything colder than absolute zero (−273.15 °C), because no temperature can be lower.
No. The conversion runs in your browser and nothing you type is sent anywhere.
Updated October 13, 2026 · More in Numbers
