Volume Converter
Convert liquid and kitchen volumes. US, UK imperial and metric cups, pints and gallons are different sizes, so each is listed separately.
US, UK and metric measures are not the same size
The biggest source of mistakes with volume is that the same name means different amounts in different countries. A US pint is 473 mL but a UK (imperial) pint is 568 mL. A US gallon is about 3.79 L and an imperial gallon about 4.55 L. Even the fluid ounce differs: a US fluid ounce is slightly larger than an imperial one, yet there are 16 US fluid ounces in a US pint and 20 imperial fluid ounces in an imperial pint.
| Measure | US customary | Imperial (UK) | Metric |
|---|---|---|---|
| Teaspoon | 4.928921594 mL | — (usually 5 mL today) | 5 mL |
| Tablespoon | 14.78676478 mL | — (usually 15 mL today) | 15 mL (20 mL in Australia) |
| Fluid ounce | 29.57352956 mL | 28.4130625 mL | — |
| Cup | 236.5882365 mL (240 mL on nutrition labels) | — (UK recipes normally use 250 mL) | 250 mL |
| Pint | 473.176473 mL | 568.26125 mL | — |
| Quart | 946.352946 mL | 1,136.5225 mL | — |
| Gallon | 3,785.411784 mL | 4,546.09 mL | — |
Which cup does my recipe use?
American recipes use the US customary cup of about 236.6 mL (half a US pint). Recipes from Australia, New Zealand, Canada and the UK that give cups normally mean the metric cup of 250 mL. The difference is about 5%, which rarely matters for soup but can matter in baking. US nutrition labels use a rounded “legal” cup of exactly 240 mL, along with 15 mL tablespoons, 5 mL teaspoons and 30 mL fluid ounces. Australia uses a 20 mL tablespoon (four teaspoons), whereas most other countries use 15 mL.
A cup measures volume, not weight. A cup of flour and a cup of sugar weigh quite different amounts, so converting cups to grams needs the density of the specific ingredient. For accurate baking, weigh ingredients where the recipe gives weights.
How the conversion works
Result = Value × (liters per “from” unit) ÷ (liters per “to” unit)
The US gallon is defined as exactly 231 cubic inches (3.785411784 L) and every US unit is a fraction of it. The imperial gallon is defined in UK law as exactly 4.54609 L. Example: 2 US cups = 2 × 236.5882365 mL = 473.176473 mL.
Common questions
How many milliliters are in a liter?
Exactly 1000. A liter is also exactly one cubic decimeter (1000 cm³), so 1 mL = 1 cm³.
How many liters is a US gallon, and a UK gallon?
A US gallon is 3.785411784 L; an imperial gallon is 4.54609 L. That is why fuel economy in miles per gallon is not comparable between the US and the UK; see the fuel economy converter.
Is 1 liter of water 1 kilogram?
Very nearly: one liter of pure water at about 4 °C has a mass of almost exactly 1 kg, and slightly less at room temperature. Other liquids differ: a liter of cooking oil weighs roughly 0.9 kg.
Sources
- Unit Conversion (SP 811 Appendix B factors and Handbook 44 Appendix C tables), National Institute of Standards and Technology (NIST)
- Weights and Measures Act 1985, Schedule 1 (definitions of imperial units), legislation.gov.uk
- Guidelines for Determining Metric Equivalents of Household Measures, U.S. Food and Drug Administration