Unit Converter
Convert between metric and imperial units for length, weight, temperature, area, volume, speed, time and digital storage. Instant and free.
About the Unit Converter
Convert any common measurement instantly: centimetres to inches, kilograms to pounds, Celsius to Fahrenheit, square feet to square metres, litres to gallons, km/h to mph and megabytes to gigabytes. See the result in every unit of the category at once.
How to use it
- Pick a category such as length or weight.
- Type a value and choose the unit you are converting from.
- Read the converted value in every other unit.
Exact conversion factors
Each unit is converted through a base unit using internationally defined factors: 1 inch is exactly 2.54 cm, 1 pound is exactly 0.45359237 kg, 1 mile is 1,609.344 m and 1 US gallon is 3.785411784 litres. Temperature uses formulas instead of factors: °F = °C × 9/5 + 32 and K = °C + 273.15.
Land and property measurements
The area converter includes perches and acres, which are still widely used for land in Sri Lanka and South Asia. One perch is 25.29 m² (about 272.25 ft²), 160 perches make an acre, and an acre is 4,046.86 m², or roughly 0.405 hectares.
Storage sizes: GB vs GiB
Drive makers use decimal units, where 1 GB is 1,000,000,000 bytes, while many operating systems report binary units, where 1 GiB is 1,073,741,824 bytes. That is why a ‘1 TB’ drive shows as about 931 GiB on your computer. Both are listed separately here so you can see the difference.
Frequently asked questions
How many centimetres are in an inch?
Exactly 2.54 centimetres, by international definition.
How do I convert Celsius to Fahrenheit?
Multiply by 9/5 and add 32. 25 °C is 77 °F.
Is a kilobyte 1,000 or 1,024 bytes?
Both are used. This tool uses decimal units (1 KB = 1,000 bytes) and binary units (1 KiB = 1,024 bytes) separately so there is no ambiguity.