Units
All-units converter
Length, weight, volume, temperature, area and speed in one converter.
How to use it
- Choose length, weight, volume, temperature, area or speed.
- Choose the unit you have and the unit you want. UK and US pints and gallons are listed separately.
- For stones, miles, fuel, cups or gas marks, the specialist page has the notes that belong to that job.
What converts by a factor
Length, weight, volume, area and speed are ratios. The page multiplies by the exact factor and divides by the target. An inch is 25.4 mm, a pound is 0.45359237 kg, a UK gallon is 4.54609 litres and a US gallon is 3.785411784 litres. A mile is 1.609344 km, and a mile per hour is that same mile per hour.
Volume lists UK and US fluid ounces, pints and gallons as different units. A UK fluid ounce is a UK gallon divided by 160. A US fluid ounce is a US gallon divided by 128. Picking “pint” without the country is the mistake this list is built to prevent.
Temperature, and when to leave this page
Temperature is not a ratio. Fahrenheit is Celsius times 9/5, plus 32. Zero Celsius is 32 Fahrenheit, so a converter that only multiplied would be wrong on every weather forecast. The temperature choice on this page uses the same formula as the Celsius page.
Stones spoken as stone and pounds, litres per 100 km, cup weights and gas marks each need a sentence of context. Those have their own pages. This one is the general bench: one amount, two units, the factor written into the result.
Questions
Does this convert US gallons to UK gallons?
Yes. Choose volume, then US gallons and UK gallons. One US gallon is 3.785411784 litres and one UK gallon is 4.54609 litres.
Why is temperature separate?
Celsius and Fahrenheit meet at different zeros. The conversion adds 32 after scaling, so it cannot share the multiply-only path used for metres and miles.