Unit Converter
Type a quantity such as 5 ft 11 in, 72 kg or 3 cups and see it in every unit of the same kind: length, weight, volume, area, temperature, speed, time, data, pressure, energy, power and fuel economy. Exact results are marked, and US and imperial units are kept apart.
Type a quantity.
What this unit converter does differently
Most unit converters answer one pair at a time, on a separate page for each kind of unit. This one reads what you type, works out the kind of unit, and lists every unit of that kind at once, so 72 kg shows pounds, stone, ounces and tonnes together. It says which answers are exact by definition and which use a rounded factor, and when a word such as gallon means different amounts in the US and the UK, it says which one it used.
| unitconverters.net | convertunits.com | This tool | |
|---|---|---|---|
| Typed quantities like 5 ft 11 in | No | Yes | Yes, with “to” for the answer unit |
| Every unit of the kind at once | On each category page | No, one pair | Yes, grouped metric, US and imperial |
| Exact or rounded, per result | No | No | Yes |
| US and imperial gallons side by side | Separate entries | Separate entries | Side by side, and says which a bare “gallon” meant |
| Compound answers (ft and in, st and lb) | No | No | Yes |
| Convert a list | No | No | Up to 5,000 values, with CSV |
| Decimal and binary data units | Yes | Yes | Yes, grouped and explained |
Home pages as fetched on 2 November 2026.
Exact conversions and where they come from
Many everyday conversions are exact because the customary units are defined in metric ones. Since the 1959 international yard and pound agreement, the yard has been exactly 0.9144 metres and the pound exactly 0.45359237 kilograms, which makes the inch exactly 2.54 cm. UK law sets the same yard and an imperial gallon of 4.54609 litres (Weights and Measures Act 1985, Schedule 1). The US gallon is 231 cubic inches, which works out at exactly 3.785411784 litres. In the US, the old survey foot was retired for new work from 2023, and NIST now uses the international foot everywhere.
The converter computes its factors from those definitions, so a result marked exact is only rounded when it is displayed. Factors that are conventions rather than definitions, such as millimetres of mercury, are tagged as rounded. All factors were checked against NIST Special Publication 811, Appendix B.8.
US and imperial units with the same name
The US and the UK use the same names for different volumes. An imperial pint is 568.26 mL and a US pint is 473.18 mL; an imperial gallon is about 20% larger than a US gallon. The fluid ounce differs too, by about 4%. Tons differ as well: a US short ton is 2,000 lb and a UK long ton is 2,240 lb, and neither is the metric tonne of 1,000 kg.
When you type a name that could mean either, the converter uses the setting under Gallons, pints, cups and tons and tells you what it chose, with a one-click switch. Cups follow the same setting: a US cup is 236.6 mL, and the UK option uses the 250 mL metric cup. Miles per gallon depends on the gallon, so 30 US mpg is about 36 imperial mpg.
Data storage: kilobytes and kibibytes
Storage makers measure in decimal units, where a gigabyte is 1,000,000,000 bytes. Some operating systems report the same space in binary units, where 1,024 bytes make the next unit up, which is why a 500 GB drive shows as about 465.66 in those systems. The IEC binary prefixes (KiB, MiB, GiB) name the binary units unambiguously. The converter lists both, grouped, so 500 GB to GiB gives the number your computer is likely to show.
How to use this converter
- Type a quantityA number and a unit, such as 72 kg, 5 ft 11 in or 3 cups.
- Pick the answer unitAdd “to lb” at the end, or choose it in To.
- Check the readingIf a unit name differs in the US and UK, the note says which one was used.
- Read every unitThe table lists all units of the same kind, with rounded factors tagged.
- Convert a listSwitch to A list, paste values one per line and choose the units.
- Copy or exportCopy the answer, download a CSV or copy a share link.