Convert any unit
Pick two units from 85 across 11 categories and enter a value. The result shows the conversion factor and the same value in every related unit, so you can sanity-check the answer.
How to use the Unit Converter
- Enter the value.
- Choose the unit you have and the unit you want (they must be the same kind of quantity).
- Click Convert; read the result and the full table.
How conversions are calculated
Every unit is stored as an exact factor to its SI base (metre, kilogram, second, square metre, litre, pascal, joule, watt). A conversion multiplies by the source factor and divides by the target factor, so chained rounding errors do not accumulate. Where an imperial unit has an exact legal definition (the international inch is exactly 25.4 mm; the pound is exactly 0.45359237 kg; the UK gallon is exactly 4.54609 L) that exact value is used. Temperature is handled separately because Celsius and Fahrenheit have offset zero points.
Metric vs imperial vs US customary
The UK and USA share inches, feet, miles and pounds but differ on volume: a US gallon is 3.785 L and a UK gallon 4.546 L, and their fluid ounces, pints and cups differ too. The tool lists them separately; pick the right one for the country. Data units are the other trap: drive makers use decimal gigabytes (10⁹ bytes) while Windows reports binary gibibytes (2³⁰) under the same "GB" label, which is why a 1 TB drive appears as 931 GB.
South Asian land units
Marla and kanal are included using the standard definition (1 marla = 272.25 sq ft, 20 marla = 1 kanal, 8 kanal = 1 acre). Some housing schemes in Pakistan use a 225 sq ft marla; check the scheme's own conversion before relying on a figure for a purchase.
Popular conversions
metres to feet · centimetres to inches · kilometres to miles · millimetres to inches · metres to yards · feet to inches · nautical miles to kilometres · kilometres to metres · centimetres to feet · kilograms to pounds · grams to ounces · kilograms to stones · pounds to ounces · tonnes to kilograms · milligrams to grams · stones to pounds · US tons to kilograms · degrees Celsius to degrees Fahrenheit · degrees Celsius to kelvins · degrees Fahrenheit to kelvins · square metres to square feet · acres to hectares · square kilometres to square miles · square feet to square yards · all converters.
Frequently asked questions
Are the conversion factors exact?
Yes for units with legal definitions (inch, foot, pound, gallon, BTU). Results are rounded for display only.
Why are there two gallons and two fluid ounces?
The USA and the UK define them differently: 3.785 L vs 4.546 L for the gallon, 29.57 ml vs 28.41 ml for the fluid ounce.
Does it work offline?
Yes. All conversions run in your browser.
Privacy
This tool runs entirely inside your browser using WebAssembly and the Canvas/File APIs. Your files are never uploaded to ToolFlint or any third party; you can verify this in your browser's network tab or by switching to airplane mode after the page loads. Read how we process files.
Last updated 2026-09-23.