Convert container capacities and liquid volumes with explicit US, imperial and metric unit labels. The same tool handles both directions.
Choose the regional unit before converting
Enter the volume, choose its source unit, then choose a destination. “US gallon” means a US liquid gallon; dry gallons are not included. A US liquid gallon is exactly 3.785411784 liters, while an imperial gallon is exactly 4.54609 liters. This difference also changes the corresponding pints, quarts and fluid ounces.
Fluid ounces are a volume, not a weight
A US gallon contains 128 US fluid ounces. An imperial gallon contains 160 imperial fluid ounces. These are two differently sized ounces: a US fluid ounce is 29.5735295625 mL; an imperial fluid ounce is 28.4130625 mL. To find a liquid's weight, you also need its density. Use the Density Calculator for mass and volume calculations.
Cups and cubic measurements
A customary US cup is half a US liquid pint. A metric cup is 250 mL, and the US nutrition-label cup is 240 mL. Check which standard a recipe or label uses. The Cooking Converter adds ingredient-dependent weight conversions.
Cubic units describe volume regardless of the material. One cubic meter contains 1,000 liters and one cubic centimeter is one milliliter. Tank capacity may differ from the usable fill volume; this tool does not account for headspace or vessel shape.
Formula
liters = US gallons × 3.785411784
liters = imperial gallons × 4.54609
US fluid ounces = US gallons × 128
imperial fluid ounces = imperial gallons × 160
Examples
Two gallon standards
5 US gallons is 18.92705892 L; 5 imperial gallons is 22.73045 L.
A cubic-foot capacity
1 ft³ is 28.316846592 L, approximately 7.48051948 US gallons.
Precision and definitions
Calculations retain unrounded values internally. Displayed digits do not increase the accuracy of measurements. NIST unit definitions provide the conversion reference.