Volume Converter
Convert liters, US and Imperial gallons, milliliters and cups.
Result
0.26417205
How it works
US and Imperial liquid measures are listed as separate units so they can never be confused.
When this question comes up
Volume conversion matters most in cooking and in anything that crosses the Atlantic. A US recipe and a UK recipe that both say “one cup” are not the same amount, and the gap is large enough to change a baking result. Fuel and tank sizes run into the same problem with gallons.
Rules and limits
- US liquid measures: 1 US gallon = 3.785411784 L and 1 US cup = 236.5882365 mL.
- Imperial measures are about 20% larger: 1 Imperial gallon = 4.54609 L and 1 Imperial cup = 284.130625 mL.
- Both systems are always labelled explicitly — there is no unit simply called “gallon”.
Worked example
1 US gal = 3.785411784 L · 1 Imperial gal = 4.54609 L
Checking the result by hand
1 US gallon = 3.785411784 L and 1 Imperial gallon = 4.54609 L — about 20% more. Cups split the same way: 236.5882365 mL in the US, 284.130625 mL in the UK. When a recipe does not say which system it uses, the country it came from is usually the safest clue.
FAQ
Which gallon does the converter use?
Whichever you select. US liquid gallon and Imperial gallon are separate entries in the unit list.
How big is an Imperial cup?
284.130625 mL, compared with 236.5882365 mL for a US cup.