Volume Converter
Convert volume between metric and both imperial systems — and yes, US and UK gallons, pints and fluid ounces are genuinely different sizes.
How it works
Volumes here are defined against the litre. Metric conversions are powers of ten, so a millilitre is exactly a cubic centimetre and a litre is exactly a cubic decimetre — those are definitions, not approximations.
The imperial units are where care is needed. A US gallon is 3.785 litres, a UK gallon is 4.546 litres — about 20% larger. Pints and fluid ounces differ the same way, so a recipe or a fuel figure means different amounts depending on which side of the Atlantic wrote it.
Confusingly, a UK fluid ounce is slightly smaller than a US one even though a UK pint is larger, because a UK pint holds 20 fluid ounces and a US pint holds 16. Both systems are offered separately here rather than averaged.
The formula
L → gal
gal = L × 0.26417205
gal → L
L = gal ÷ 0.26417205
Any pair in this family
result = value × (factor of source ÷ factor of target)
Every unit is defined against the l, so any combination converts in one step.
Worked examples
| Scenario | Working | Result |
|---|---|---|
| 1 litre to US gallons | 1 ÷ 3.785412 | 0.2642 US gal |
| 1 UK gallon to litres | 1 × 4.54609 | 4.546 L |
| 1 US pint vs 1 UK pint | 473 ml vs 568 ml | The UK pint is 20% larger |
When you'd use it
- Converting fuel consumption or tank capacity
- Following a recipe written in the other system
- Reading a bottle or container label
- Converting between cubic measures and litres
Common questions
Is a US gallon the same as a UK gallon?
No, and the gap is large. A US gallon is 3.785 litres; a UK (imperial) gallon is 4.546 litres, about 20% bigger. Fuel economy figures in mpg are not comparable between the two without converting.
Why is a UK fluid ounce smaller but a UK pint bigger?
Because a UK pint contains 20 fluid ounces while a US pint contains 16. The individual ounce is slightly smaller in the UK, but there are more of them, so the pint ends up larger.
Is a millilitre the same as a cubic centimetre?
Yes, exactly. One millilitre is defined as one cubic centimetre, which is why medical and engineering documents use ml and cc interchangeably.
Is anything I enter sent anywhere?
No. Every conversion runs in your browser, so nothing you type is uploaded, logged or stored. There is no account and no record of what you converted.