Volume Converter
Volume is where US and UK units quietly diverge: a US gallon is 3.785 L but an imperial gallon is 4.546 L, a 20% difference. This converter keeps both systems separate so you never mix them by accident.
Last updated — conversions use exact unit definitions, so results stay accurate.
| Unit | Value |
|---|
How it works
All volume conversions here run through the liter. Metric units are straightforward powers of ten: 1,000 mL in a liter and 1,000 liters in a cubic meter. The US customary units derive from the gallon, which is defined as exactly 231 cubic inches, or 3.785411784 L.
The UK imperial gallon is a different animal: 4.54609 L, about 20% larger than the US gallon. Because both are called "gallon", the mistake is easy to make and expensive to correct — a 20% error in fuel, paint or batch cooking. If a recipe or datasheet does not say which gallon it means, the country of origin is usually the giveaway.
Fluid ounces differ too. A US fluid ounce is 29.5735 mL while an imperial fluid ounce is 28.4131 mL. The difference is small per ounce but compounds: a US pint is 473 mL against 568 mL for an imperial pint, which is why a British pint of beer looks noticeably larger.
Teaspoons and tablespoons in this tool use US measures (4.93 mL and 14.79 mL). Australian tablespoons are 20 mL, so an Australian recipe calling for a tablespoon is asking for somewhat more than an American one.
Common volume conversions
| From | To |
|---|---|
| 1 liter | 33.814 US fl oz |
| 1 liter | 4.2268 US cups |
| 1 US gallon | 3.7854 L |
| 1 UK gallon | 4.5461 L |
| 1 US cup | 236.59 mL |
| 1 US fl oz | 29.5735 mL |
| 1 UK fl oz | 28.4131 mL |
| 1 US pint | 473.18 mL |
| 1 UK pint | 568.26 mL |
| 1 cubic meter | 1,000 L |
Frequently asked questions
Is a US gallon the same as a UK gallon?
No. A US gallon is 3.785 L while an imperial (UK) gallon is 4.546 L, roughly 20% larger. The converter lists both separately — check which system your source uses, because mixing them produces a large error in fuel, paint or bulk recipes.
How many cups are in a liter?
A US cup is 236.59 mL, so 1 liter is about 4.23 US cups. If you are working with the metric cup used in Australia and the UK (250 mL), 1 liter is exactly 4 cups. Recipes rarely state which cup they mean, so weighing ingredients in grams avoids the ambiguity entirely.
How many milliliters are in a fluid ounce?
A US fluid ounce is 29.5735 mL and an imperial fluid ounce is 28.4131 mL. The difference is about 4%, small enough to ignore for a single ounce but significant when scaling a recipe up.
Is a fluid ounce the same as an ounce of weight?
No — a fluid ounce measures volume and an ounce measures weight. They coincide only for water: 1 US fl oz of water weighs about 1.04 oz. For flour, sugar or oil the weight per fluid ounce differs, which is why volume and weight are not interchangeable in baking.
How do I convert liters to gallons?
Divide liters by 3.785411784 for US gallons, or by 4.54609 for imperial gallons. For example, 10 L is 2.64 US gallons or 2.20 UK gallons.