ToolPikaHow it works
Every unit is stored as its size in liters, and the converter multiplies by the ratio between the two units. All factors are exact by definition:
- The US gallon is exactly 231 cubic inches, or 3.785411784 L. A US quart is ¼ gallon, a pint ⅛, a cup 1/16 and a fluid ounce 1/128.
- The UK (imperial) gallon is exactly 4.54609 L. A UK pint is ⅛ gallon (568 ml) and a UK fluid ounce 1/160 gallon.
- Cubic units come from the 1959 inch: 1 in³ = 16.387064 ml, 1 ft³ = 28.316846592 L.
- Metric: 1 L = 1,000 ml = 1 dm³, and 1 m³ = 1,000 L.
US and UK measures side by side
| Unit | US | UK (imperial) |
|---|---|---|
| Fluid ounce | 29.57 ml | 28.41 ml |
| Pint | 473.18 ml (16 fl oz) | 568.26 ml (20 fl oz) |
| Gallon | 3.785 L | 4.546 L |
Note that a US fluid ounce is slightly larger than a UK one, but a US pint is smaller, because a US pint holds 16 fl oz and a UK pint holds 20.
Examples
- Cooking. 2 liters of stock is 8.45 US cups; a 12 US fl oz can is 354.9 ml.
- Fuel. 50 liters is 13.21 US gallons or 11 UK gallons.
- Beer. A UK pint (568 ml) is about 20% larger than a US pint (473 ml).
- Aquariums and ponds. A tank of 1 ft³ holds 28.32 liters.