Unit converter

How it works

Choose a quantity, such as length, temperature or computer data.
Pick the unit you have and the unit you want, then type a number on either side.
Use the swap button to turn the conversion round, and read every other unit in the table below.

Temperature is different

Most units differ only by a factor: a mile is always 1.609344 kilometres. Temperature scales also have different zero points, so the converter adds or subtracts an offset as well. 0 °C is 32 °F and 273.15 K, and −40 is the one temperature that reads the same in Celsius and Fahrenheit.

Typing numbers

You can use a comma or a point as the decimal separator, spaces between thousands and powers of ten such as 2e9. The precision setting rounds to the chosen number of significant digits, and very large or very small results are shown in scientific notation.

Frequently asked questions

Why is my 1 TB drive shown as 931 GB?

Drive makers count in powers of 1000, so 1 TB is 10¹² bytes. Many operating systems count in powers of 1024 but still write GB, and 10¹² bytes is about 931 GiB. Choose TB and GiB here to see it.

Is weight the same as mass?

Not quite. Mass is the amount of matter and is measured in kilograms; weight is the force of gravity on it. In everyday use, though, kilograms and pounds are called weight, and that is what this converter means.

Which gallon does it use?

Both. The US gallon is 3.785 litres and the imperial gallon used in the UK is 4.546 litres, so they are listed separately, just like the US and imperial pint and cup.