Volume Converter
Convert between milliliters, liters, gallons, cups, and more.
Quick reference
- 1 US gallon = 3.785 liters
- 1 liter ≈ 0.264 US gallons
- 1 US quart = 0.946 liters
- 1 US cup ≈ 236.6 mL
- 1 US fluid ounce ≈ 29.57 mL
About this converter
Cooking and fuel/liquid measurements are where this comes up most: a recipe from a different country, a fuel tank spec, a bottle size that doesn't match what you're used to. It handles metric volumes (milliliters, liters, cubic meters) on one side and US customary units (gallons, quarts, pints, cups, fluid ounces) on the other.
Here's a detail that catches a lot of people off guard: a US gallon and a UK (imperial) gallon are not the same size, and never have been. The US kept the old English wine gallon from before independence (231 cubic inches, about 3.785 liters). Britain redefined its gallon in 1824 based on the volume of 10 pounds of water, which came out bigger, about 4.546 liters. So if a recipe or a fuel figure says "gallon" without saying which, it genuinely matters which side of the Atlantic it came from.
Frequently asked questions
- Are these US or UK gallons and cups?
- US customary units throughout. If you're working from a UK recipe or a UK fuel figure, double check, since a UK gallon (about 4.546 L) is noticeably bigger than a US gallon (about 3.785 L), and UK/US cups and fluid ounces aren't identical either.
- Why is a US gallon smaller than a UK gallon?
- The US kept the old British wine gallon from the colonial era. Britain later redefined its own gallon (in 1824) using a different reference, water instead of wine, and ended up with a bigger unit. The US never adopted the change, so the gap has been there ever since.
- Is a metric cup the same as a US cup?
- No. A US cup is about 236.6 mL; the "metric cup" some countries use (Australia, for one) is a rounder 250 mL. Close enough for casual cooking, not close enough for baking where ratios matter.