Cups to Gallons Converter — US Customary Volume
Convert any number of US cups to gallons and other volume units instantly. Essential for scaling recipes, measuring beverages and comparing cooking quantities.
cup
1 US gallon = 16 US cups (exact)
- 1
Cups per gallon
161 US gallon = 16 US cups exactly (4 quarts × 2 pints × 2 cups) - 2
Gallons = cups ÷ 16
16 ÷ 16 = 1
How does this calculator work?
US gallons = cups ÷ 16. There are exactly 16 US cups in 1 US gallon (4 quarts × 2 pints × 2 cups = 16). 1 US cup = 8 fl oz = 236.588 mL. For metric: multiply cups by 236.588 for mL, or divide by 4.227 for litres.
Formula
How this is calculated
US customary volume units follow exact integer ratios. A US gallon contains exactly 4 quarts, 8 pints, 16 cups and 128 fluid ounces. So dividing the cup count by 16 gives the exact gallon equivalent — no rounding is needed. Multiplying by 8 gives fluid ounces. Dividing by 4 gives quarts. Dividing by 2 gives pints.
For metric conversions, one US cup is defined as exactly 236.5882365 mL (half a US pint = 8 US fluid ounces). This is a legal definition, so the mL and litre results are also exact to the number of decimal places shown, not approximations.
Note that these conversions are for US customary cups and gallons only. The imperial (UK) cup is 284 mL (not in common use today), the imperial gallon is 4.546 L, and the US dry gallon is 4.405 L — all different from the US fluid gallon of 3.785 L used here. If you are following a UK recipe, check which cup size is intended.
Frequently asked questions
There are exactly 16 US cups in 1 US gallon. The relationship follows from the chain: 1 gallon = 4 quarts, 1 quart = 2 pints, 1 pint = 2 cups, so 4 × 2 × 2 = 16 cups per gallon.
A half-gallon equals 8 US cups. This is a common size for juice and milk cartons in the United States.
This converter uses US customary cups (1 cup = 8 US fl oz = 236.588 mL) and the US fluid gallon (1 gallon = 3.785 L). UK recipes sometimes use a 284 mL "imperial cup," but that unit is rarely seen today — most UK recipes now use millilitres.
TG we-Calculate Editorial Team. (2026). Cups to Gallons Converter — US Customary Volume [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/cups-to-gallons-converter
TG we-Calculate Editorial Team. "Cups to Gallons Converter — US Customary Volume." TG we-Calculate. 2026. https://we-calculate.com/calculator/cups-to-gallons-converter.
TG we-Calculate Editorial Team, "Cups to Gallons Converter — US Customary Volume," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/cups-to-gallons-converter
@misc{wecalculate_cups_to_gallons_converter, title = {Cups to Gallons Converter — US Customary Volume}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/cups-to-gallons-converter}}, year = {2026}, note = {TG we-Calculate} }
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