Volume Converter
Convert litres, millilitres and cubic metres to US and imperial gallons, pints, cups and fluid ounces — including the difference between a US pint and an imperial pint. Results update as you type; exact factors shown.
One litre is 0.22 imperial gallons — see the exact factor, not a rounded rule of thumb.
How the volume converter works
Volumes convert through the litre (exactly 1 dm³). The US gallon is exactly 3.785411784 L (231 cubic inches); the imperial gallon is exactly 4.54609 L. A US fluid ounce is 29.5735 mL, an imperial fluid ounce 28.4131 mL; a US pint is 16 US fl oz, an imperial pint 20 imperial fl oz.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common volume conversions
| From | To | Units |
|---|---|---|
| 1 L | 0.2642 US gal | litre to US gallons |
| 1 US gal | 3.7854 L | US gallon to litres |
| 1 imp gal | 4.5461 L | imperial gallon to litres |
| 1 imp pt | 568.2613 mL | imperial pint to millilitres |
| 1 US pt | 473.1765 mL | US pint to millilitres |
| 1 US cup | 236.5882 mL | US cup to millilitres |
| 1 US fl oz | 29.5735 mL | US fluid ounce to millilitres |
| 1 m³ | 1,000 L | cubic metre to litres |
| 1 ft³ | 28.3168 L | cubic foot to litres |
| 1 L | 1,000 mL | litre to millilitres |
Units in this converter and their exact factors
| Unit | Symbol | One unit in litres |
|---|---|---|
| millilitre | mL | 0.001 litre |
| litre | L | 1 litre |
| cubic metre | m³ | 1,000 litre |
| teaspoon (metric) | tsp | 0.005 litre |
| tablespoon (metric) | tbsp | 0.015 litre |
| cup (metric) | cup | 0.25 litre |
| US fluid ounce | US fl oz | 0.0295735296 litre |
| US cup | US cup | 0.2365882365 litre |
| US pint | US pt | 0.473176473 litre |
| US gallon | US gal | 3.785411784 litre |
| imperial fluid ounce | imp fl oz | 0.0284130625 litre |
| imperial pint | imp pt | 0.56826125 litre |
| imperial gallon | imp gal | 4.54609 litre |
| cubic foot | ft³ | 28.316846592 litre |
FAQFrequently asked questions about volume conversion
Why are US and imperial gallons different?
The US kept the old English wine gallon (231 cubic inches, 3.785 L) after independence; the UK redefined its gallon in 1824 as the volume of 10 pounds of water (4.546 L). The imperial gallon is about 20% larger.
How many millilitres are in a cup?
A metric cup is 250 mL; a US customary cup is 236.6 mL; a US "legal" cup on nutrition labels is 240 mL.
How many litres are in a cubic metre?
Exactly 1,000 litres.
Is a UK pint bigger than a US pint?
Yes — an imperial pint is 568 mL, a US pint 473 mL.
How many litres in a US gallon?
Exactly 3.785411784 L. The imperial gallon is 4.54609 L.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.