Metric and imperial volume conversions
Volume Converter
Convert millilitres, litres, US fluid ounces, cups, pints and US gallons instantly with our free online volume converter. No signup required, works offline.
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How to Convert Volume Units
Volume conversions are essential for cooking, baking, mixing drinks, measuring fuel, and understanding product sizes. The metric system (millilitres and litres) is used for most scientific and everyday measurement around the world, while US customary units (cups, pints, fluid ounces, gallons) dominate American recipes and product labelling. The UK adds its own twist: an imperial pint is 568 ml, while a US pint is 473 ml.
Key Volume Conversion Formulas
1 US gallon = 3.78541 litres
1 US pint = 473.18 ml (an imperial pint is 568.26 ml)
1 US cup = 236.59 ml
1 US fl oz = 29.57 ml
This converter uses US customary units for cups, pints, fluid ounces and gallons, which are the versions used in American recipes and by most international standards bodies when quoting US measures. Litres and millilitres are the same worldwide.
Common Volume Conversions
| Unit | Equals | Real-world reference |
|---|---|---|
| 1 litre (L) | 33.81 US fl oz | A large bottle of soft drink |
| 1 US gallon | 3.785 L | A gallon of milk in the US |
| 1 US cup | 236.6 ml | Standard US measuring cup |
| 1 US pint | 473.2 ml | A US pint of beer (vs 568 ml in the UK) |
| 1 US fl oz | 29.57 ml | A shot glass is roughly 1.5 fl oz |
| 1 millilitre (ml) | 0.034 US fl oz | 20 drops of water |
Where Volume Conversion Matters
- Cooking and baking: US recipes use cups and fluid ounces; European recipes use grams and millilitres. Getting the conversion right is the difference between a cake and a pancake
- Fuel economy: Compare miles per gallon with litres per 100 km when evaluating vehicles
- Beverages: Understanding pint and litre sizes when buying drinks in different countries
- Medicine and chemistry: Precise millilitre measurements for dosing and experiments
- Gardening and DIY: Mixing chemicals, paints and fertilisers by volume
US vs Imperial Volume Units
The most common source of confusion in volume conversion is the difference between US and imperial measures. Both systems have units called pints, fluid ounces and gallons, but they are different sizes. A US gallon is 3.785 litres while an imperial gallon is 4.546 litres (about 20% larger). A US fluid ounce is 29.57 ml while an imperial fluid ounce is 28.41 ml. This tool uses US customary units throughout, so results match American recipes, US product labels, and the units used in most international reference tables.
Frequently Asked Questions
How many litres are in a gallon?
One US gallon is 3.78541 litres. To convert gallons to litres, multiply by 3.785. To convert litres to gallons, divide by 3.785. Our volume converter handles this instantly.
How many millilitres are in a cup?
One US cup is exactly 236.588 millilitres, usually rounded to 240 ml in recipes. Note that metric cups in Australia and New Zealand are 250 ml.
Is a UK pint bigger than a US pint?
Yes. An imperial (UK) pint is 568 ml while a US pint is 473 ml, so a UK pint is about 20% larger. This is why a pint of beer differs between the two countries.
How many cups are in a litre?
One litre equals approximately 4.23 US cups. To convert litres to cups, multiply by 4.23. For cooking, 1 litre is usually treated as 4 cups.
How do I convert fluid ounces to millilitres?
Multiply the number of US fluid ounces by 29.57 to get millilitres. For example, 8 fl oz (one US cup) is 236.6 ml.
Does the volume converter work offline?
Yes, the converter runs entirely in your browser. Once loaded, all conversions happen locally with no server calls and no data collection.