How Unit Conversion Works

Conversion factors

A conversion factor expresses how two units relate. For example, 1 kilometre equals 1,000 metres, so kilometres can be converted to metres by multiplying by 1,000.

Temperature uses formulas

Temperature scales have different zero points, so temperature conversions use formulas rather than one multiplication factor. Celsius to Fahrenheit is a common example.

Check the direction

Converting a larger unit into a smaller unit often increases the numeric value. Converting the other way usually decreases it. Always check the source and target units before using a result.

Convert instantly

Use the Unit Converter to switch between common length, weight, volume and temperature units.