Volume Converter
Convert liters, gallons, cups, and fluid ounces for recipes and more.
Convert volumes between liters, milliliters, US gallons, fluid ounces, and cups. Perfect for recipes, fuel, and lab work — using the US customary definitions cooks actually use.
How it's calculated
Every unit converts through liters with its exact factor: 1 US gallon = 3.785411784 L, 1 US fluid ounce = 0.0295735295625 L, 1 US cup = 0.2365882365 L. The result is value × factor[from] ÷ factor[to].
Frequently asked questions
How many liters are in a US gallon?
3.78541 liters. Enter 1, choose gal → L — the US liquid gallon is exactly 3.785411784 liters.
How many fluid ounces are in a cup?
8 fluid ounces. Enter 1, choose cup → fl oz — a US cup is defined as 8 US fluid ounces.
US or imperial gallons?
This uses US customary units (the ones in American recipes and fuel pumps). An imperial gallon is larger — 4.54609 liters.