🧪 Volume Converter
Convert between liters, gallons, cups, and fluid ounces.
About this tool
Converts between eight volume units — liters, milliliters, US gallons, quarts, pints, cups, fluid ounces, and the UK imperial gallon — through a shared liter base.
Covers both the US and UK gallon, which is a common source of confusion since the two differ by about 20%.
Worked example
1 US gallon is about 3.785 L, while 1 imperial (UK) gallon is about 4.546 L — noticeably more.
How to use it
- Enter a value.
- Choose the unit you're converting from.
- Choose the unit you want, and press Convert.
Tips
- Double-check whether a recipe or spec sheet means US or imperial gallons — this tool includes both, clearly labeled.
- Cooking measurements (cups, fl oz) are US customary by default here.
- For a single fast liters↔gallons conversion, our dedicated pair page uses the US gallon by default.
FAQ
Why are there two kinds of gallons?
The US and UK historically defined the gallon differently; the US gallon (3.785 L) is smaller than the imperial gallon (4.546 L) still used in some Commonwealth contexts.
Is a US cup the same everywhere?
No — this tool uses the US customary cup (240 mL); some other countries define "cup" slightly differently for recipes.
How many fluid ounces are in a US gallon?
128 fl oz.
From the blog: getting the most out of this tool
Volume conversions are where unit ambiguity causes the most real mistakes — a US recipe cup isn't quite the same as some other countries' cup, and a US gallon is meaningfully smaller than a UK gallon.
We labeled both gallon types explicitly rather than picking one silently, because guessing wrong here can throw off a recipe or a fuel estimate by a fifth.