Unit Converter
Open toolConvert length, weight, and temperature units.
Convert a length, weight or temperature from one unit to another. Enter a value, choose the units, and read the answer immediately.
How it works
Length and weight are converted in two steps: your value is first turned into a base unit (metres for length, kilograms for weight) and then into the unit you asked for. Temperature uses its own formulas through degrees Celsius: °F = °C × 9/5 + 32, and K = °C + 273.15.
The answer is rounded to at most six decimal places, with trailing zeros dropped, so 1 m to feet reads 3.28084. The result updates as you type.
How to use it
- Choose Length, Weight or Temperature at the top.
- Enter the Value you want to convert.
- Pick the unit you are converting From and the unit you want To.
- Read the result in the panel, and click Copy to copy it with its unit.
Options & controls
Category
- Length / Weight / Temperature
- Switches the list of units. When you switch, From and To are set to the first two units of the new category and the Value stays as it is.
Conversion
- Value
- Any number, including decimals and negatives. If it is empty or not a number, the result shows a dash. Default: 1.
- From
- The unit your value is in. Default: m.
- To
- The unit you want. Default: ft.
- Copy
- Copies the result followed by its unit, for example
3.28084 ft. Only shown when there is a result. - Reset
- In the title row. Returns to Length, 1 m to ft.
Length units
- mm, cm, m, km
- Millimetres, centimetres, metres, kilometres.
- in, ft, yd, mi
- Inches, feet, yards, miles (statute miles, 1 mi = 1,609.344 m).
Weight units
- mg, g, kg
- Milligrams, grams, kilograms.
- tonne
- The metric tonne, 1,000 kg. Not the US short ton or UK long ton.
- oz, lb
- Ounces and pounds (avoirdupois, so 16 oz = 1 lb).
Temperature units
- C, F, K
- Degrees Celsius, degrees Fahrenheit, and kelvin.
Tips & guidelines
- Converting a unit to itself just returns the same number, which is a quick way to check you have chosen what you meant.
- For a fine distinction — say, millimetres to kilometres — the answer may be a very small number. Choose intermediate units if the rounded result looks like 0.
- Temperature conversions are of a reading, not of a difference: 10 °C is 50 °F, but a rise of 10 °C is a rise of 18 °F.
Limits
- Only length, weight and temperature. Area, volume, speed, time, data size and other categories are not included.
- Conversion factors for ounces and pounds are rounded to six significant digits, so results can differ from an exact conversion in the seventh digit.
- The tool does not warn about physically impossible values, such as a temperature below absolute zero.
- Results are shown to six decimal places at most; extremely large or small numbers may appear in scientific notation.
Saved in your browser
Nothing. Selections reset to the defaults when you refresh.