Gallons to Cups Converter — US & Imperial
Find out how many cups are in a gallon — for US or Imperial gallons — and also get the equivalent in pints, quarts, fluid ounces, tablespoons and teaspoons all at once.
gal
Gallon type
1 US gallon = 16 US cups (8 fl oz each)
- 1
Cups per gallon
16Exactly 16 US cups in 1 US gallon (each cup = 8 fl oz). - 2
Total cups
1 × 16 = 16
How does this calculator work?
1 US gallon = 16 US cups = 32 half-cups = 8 pints = 4 quarts = 128 fl oz = 256 tbsp = 768 tsp. Imperial ratios are the same but the fluid ounce is slightly larger (~20%), so an Imperial cup ≈ 284 mL vs a US cup ≈ 237 mL. These ratios are exact by definition.
Formula
How this is calculated
The US customary system defines a gallon as 128 US fluid ounces. A US cup equals 8 fl oz, so one US gallon contains exactly 16 US cups. The subdivisions nest cleanly: 2 cups = 1 pint, 2 pints = 1 quart, and 4 quarts = 1 gallon. Tablespoons and teaspoons extend the chain: 1 US cup = 16 tablespoons = 48 teaspoons (using the modern US definition of 1 tbsp = 3 tsp = ½ fl oz).
The Imperial cup (used in older UK and Canadian recipes) is 10 Imperial fluid ounces, but the gallon-to-cup ratio is the same: 1 Imperial gallon still divides into exactly 16 cups. However, the underlying fluid ounce is larger (1 Imperial fl oz ≈ 28.41 mL versus 1 US fl oz = 29.57 mL), so an Imperial cup ≈ 284 mL compared to a US cup ≈ 237 mL. This matters when following older British recipes with a US measuring cup.
For cooking conversions the key facts to remember are: 1 US gallon = 16 cups = 32 half-cups (the standard "cup" measure) = 256 tablespoons = 768 teaspoons. These are exact by definition, not rounded approximations.
Frequently asked questions
1 US liquid gallon = exactly 16 US cups (each cup = 8 fl oz). 1 Imperial gallon also = 16 Imperial cups (each cup = 10 Imperial fl oz, which are slightly larger than US fl oz).
1 US gallon = 16 cups × 16 tablespoons/cup = 256 US tablespoons = 768 teaspoons. These are exact under the US customary definitions.
A US cup = 8 US fl oz ≈ 236.6 mL. An Imperial (UK) cup = 10 Imperial fl oz ≈ 284.1 mL — about 20% larger. Both give 16 cups per gallon because each uses its own gallon standard. Always check which system a recipe uses to avoid measuring errors.
Also known as
TG we-Calculate Editorial Team. (2026). Gallons to Cups Converter — US & Imperial [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/gallons-to-cups-converter
TG we-Calculate Editorial Team. "Gallons to Cups Converter — US & Imperial." TG we-Calculate. 2026. https://we-calculate.com/calculator/gallons-to-cups-converter.
TG we-Calculate Editorial Team, "Gallons to Cups Converter — US & Imperial," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/gallons-to-cups-converter
@misc{wecalculate_gallons_to_cups_converter, title = {Gallons to Cups Converter — US & Imperial}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/gallons-to-cups-converter}}, year = {2026}, note = {TG we-Calculate} }
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