Convert US Gallons to Cups

About converting US Gallons to Cups

US Gallons (gal (US)) and Cups (cup) are both units of volume, so converting between them is a single multiplication: multiply your US Gallons figure by 16. Ten US Gallons comes to 160 Cups, and a hundred works out at 1,600 Cups.

Rule of thumb: going from US Gallons to Cups multiplies, so the figure always grows — one US Gallon is already 16 Cups. If your answer came out smaller, you have the conversion the wrong way round.

What is an US Gallon?

The US gallon is defined as exactly 231 cubic inches, a figure inherited unchanged from the old English wine gallon. When Britain overhauled its measures in 1824 and adopted a new imperial gallon, the United States simply kept the wine gallon it already had — and that single decision is the root of the entire US-versus-imperial mess that still catches people out today. The US gallon is roughly a fifth smaller than the imperial one, which means American and British fuel-economy figures are not comparable even though both are quoted in miles per gallon.

What is a Cup?

The cup is a cooking unit and nothing else — no scientific or trade use — and it is dangerously ambiguous. The US customary cup in recipes is about 237 mL, the metric cup used in Australia and much of Europe is exactly 250 mL, and the US legal cup that nutrition labels are calculated against is 240 mL, different again from the one in the cookbook. Recipes almost never say which they mean. The problem compounds for dry goods, since a cup measures volume while baking actually depends on mass: how hard you pack the flour changes the answer.

To put both in perspective: a typical American milk jug holds one US gallon, while a cup is the measure American recipes count flour in.

The converter above updates as you type, and the table lists common values for quick reference. Need the opposite direction? Use the Cups to US Gallons converter, or browse all Volume converters.