How to convert volume units
Select the unit you have in From and the unit you want in To, enter the amount and press Convert. US and imperial units are listed separately, so check which one your recipe, label or fuel figure uses. Negative volumes are rejected.
How the conversion works
Every unit is stored as a number of cubic meters. A liter is one cubic decimeter, 0.001 m³, and a milliliter is exactly one cubic centimeter. The US gallon is defined as 231 cubic inches, which is exactly 3.785411784 L, while the imperial gallon used in the UK is exactly 4.54609 L.
The smaller US units follow from the gallon: 1 gallon = 4 quarts = 8 pints = 16 cups = 128 fluid ounces, a cup is 16 tablespoons and a tablespoon is 3 teaspoons. The imperial gallon also has 4 quarts and 8 pints, but 160 fluid ounces, so an imperial pint holds 20 fluid ounces instead of 16.
| Volume | Equals |
|---|---|
| 1 US gallon | 3.785411784 L |
| 1 imperial gallon | 4.54609 L |
| 1 US cup | 236.5882365 mL |
| 1 US fluid ounce | 29.5735295625 mL |
| 1 imperial fluid ounce | 28.4130625 mL |
| 1 cubic inch | 16.387064 cm³ |
| 1 cubic foot | 28.316846592 L |
| 1 liter | ≈ 0.264172 gal (US) |
| 1 cubic meter | ≈ 35.314667 ft³ |
Worked examples
- A 12 US gallon fuel tank in liters: 12 × 3.785411784 ≈ 45.42 L.
- A 2 L bottle in US fluid ounces: 2,000 mL ÷ 29.5735295625 ≈ 67.63 fl oz.
- 1½ US cups in milliliters: 1.5 × 236.5882365 ≈ 354.88 mL.
- Concrete for a 10 ft × 12 ft slab, 4 in thick: 4 in is 1/3 ft, so the volume is 10 × 12 × 1/3 = 40 ft³. A cubic yard is 27 ft³, so that is 40 ÷ 27 ≈ 1.48 yd³, or about 1.13 m³.
Liters to gallons
| L | gal (US) | gal (UK) |
|---|---|---|
| 1 | 0.264 | 0.22 |
| 5 | 1.321 | 1.1 |
| 10 | 2.642 | 2.2 |
| 20 | 5.283 | 4.399 |
| 50 | 13.209 | 10.998 |
| 100 | 26.417 | 21.997 |
US cups and fluid ounces
| cup (US) | mL | fl oz (US) | tbsp (US) |
|---|---|---|---|
| 0.25 | 59.15 | 2 | 4 |
| 0.5 | 118.29 | 4 | 8 |
| 0.75 | 177.44 | 6 | 12 |
| 1 | 236.59 | 8 | 16 |
| 2 | 473.18 | 16 | 32 |
| 4 | 946.35 | 32 | 64 |
| fl oz (US) | mL |
|---|---|
| 1 | 29.57 |
| 4 | 118.29 |
| 8 | 236.59 |
| 12 | 354.88 |
| 16 | 473.18 |
| 32 | 946.35 |
Units that are easy to confuse
- US and imperial gallons. An imperial gallon is about 1.201 US gallons. UK fuel economy figures in miles per gallon use imperial gallons, so they cannot be compared directly with US figures; the fuel consumption converter handles that.
- Pints and fluid ounces. A UK pint is about 568.26 mL and a US pint about 473.18 mL. Yet the imperial fluid ounce (about 28.41 mL) is smaller than the US fluid ounce (about 29.57 mL). The UK pint is larger because it holds 20 of its ounces.
- Cups. The US customary cup is 236.5882365 mL. The metric cup used in Australia, New Zealand and other countries is 250 mL, about 5.7% more. US nutrition labels use a third value, 240 mL, with a 30 mL fluid ounce; that labeling cup is not a separate unit here, so enter it as 240 mL.
- Spoons. A US tablespoon is about 14.79 mL and a metric tablespoon 15 mL, which rarely matters in a recipe. The Australian tablespoon is 20 mL and is not included.
- Liquid and dry measures. The US pints, quarts and gallons here are liquid measures. The US dry pint, used for produce, is 33.6 in³ (about 550.61 mL) and is not included.
- Barrels. The barrel here is the 42 US gallon petroleum barrel, about 158.99 L. Barrels for beer and other goods are different sizes.
Common mistakes
- Using a length factor for cubic units. A meter is about 3.28 ft, but a cubic meter is about 35.31 ft³. Cubing a rounded 3.28 gives 35.29, so round only at the end.
- Treating volume as weight. A cup of flour and a cup of water fill the same volume but do not weigh the same. This tool converts volume only; for ounces or grams by weight use the weight converter with a weighed amount.
- Assuming every "ounce" is a fluid ounce. Fluid ounces measure volume; ounces on a kitchen scale measure mass.
Frequently asked questions
How many milliliters are in a cup?
It depends on the cup: about 236.59 mL for a US customary cup, 250 mL for a metric cup and 240 mL on US nutrition labels.
How many liters are in a gallon?
About 3.785 L in a US gallon and 4.546 L in an imperial gallon.
How many cubic feet are in a cubic yard?
Exactly 27, since a yard is 3 feet and 3 × 3 × 3 = 27. A cubic yard is about 0.7646 m³.
What is an acre-foot?
The volume of water that covers one acre to a depth of one foot: 43,560 ft³, about 1,233.48 m³ or about 325,851 US gallons. It is used for reservoirs and irrigation in the United States.
Supported units
- Cubic meter (m³)
- Hectoliter (hL)
- Liter (L)
- Deciliter (dL)
- Centiliter (cL)
- Milliliter (mL)
- Microliter (µL)
- Cubic centimeter (cm³)
- Cubic millimeter (mm³)
- Gallon (US) (gal (US))
- Quart (US) (qt (US))
- Pint (US) (pt (US))
- Cup (US customary) (cup (US))
- Fluid ounce (US) (fl oz (US))
- Tablespoon (US) (tbsp (US))
- Teaspoon (US) (tsp (US))
- Gallon (imperial) (gal (UK))
- Quart (imperial) (qt (UK))
- Pint (imperial) (pt (UK))
- Fluid ounce (imperial) (fl oz (UK))
- Cup (metric) (cup (metric))
- Tablespoon (metric) (tbsp (metric))
- Teaspoon (metric) (tsp (metric))
- Cubic inch (in³)
- Cubic foot (ft³)
- Cubic yard (yd³)
- Barrel (oil, 42 US gal) (bbl)
- Acre-foot (ac·ft)