Volume Converter
Convert a volume between milliliters, liters, cubic centimeters, cubic meters, US gallons, quarts, pints, fluid ounces and cups. All of the liquid measures here are US customary; the imperial gallon is a different, larger unit.
US liquid measures throughout: 1 gal = 3.785411784 L, and a UK imperial gallon is 4.54609 L.
Formula and calculation
Worked example
One US gallon is 3.7854 liters. The factor line reads 1 gal = 3.785412 L, so 5 gallons work out as 5 × 3.785412 = 18.92706 L.
Cups, tablespoons and fluid ounces in the kitchen
US recipes use volume, not weight, so the chain worth knowing is: 1 cup = 8 fl oz = 16 tbsp = 48 tsp = 236.5882365 mL. Half a cup is 4 fl oz, and two cups make a pint. Nutrition labels use a slightly different cup of exactly 240 mL, about 1.4% larger than the measuring cup in your drawer, which is why label conversions never quite match a kitchen scale. For anything where the ratio matters — bread, pastry, cocktails in bulk — weigh the ingredients in grams or milliliters instead of counting cups.
What the results mean
- 1 gal =
- Your volume converted to the target unit, using the exact defined measures (1 US gallon is exactly 3.785411784 liters).
- Conversion factor
- The one-way factor for this pair, so you can repeat the arithmetic by hand: value x factor = result.
- Reverse
- The same factor in the opposite direction, for converting a result back later.
Frequently asked questions
How many milliliters are in a cup?
236.5882365 mL for the US customary cup, which is 1/16 of a US gallon and what a standard US measuring cup holds. Nutrition labels use a legal cup of exactly 240 mL, which is about 1.4% larger.
Is a US gallon the same as a UK gallon?
No. A US liquid gallon is 3.785411784 L and a UK imperial gallon is 4.54609 L, roughly 20% more. The imperial fluid ounce is actually smaller (28.4130625 mL against 29.5735295625 mL) because the imperial gallon is split into 160 of them instead of 128.
How many ounces are in a liter?
33.814 US fluid ounces, because one fluid ounce is 29.5735 mL. A 2 liter bottle therefore holds 67.6 fl oz, a little over half a US gallon, which is why metric bottles are a common size for soda.
What is 750 ml in ounces?
25.36 US fluid ounces, the standard wine bottle. It is close to the old US fifth of a gallon (757 mL), which is where the name comes from — the 750 mL size was adopted when US bottlers switched to metric.