Gallons to cups conversion factors are listed below (for US, UK and for both fluid and dry measurements). To find out how many cups in a gallon, multiply by the conversion factor or use the converter if the conversion is from US fluid gallons to US cups. 1 Gallon [Fluid, US] = 16 Cups [US], 1 Gallon [Dry, US] = 18.618355 Cups [US], 1 Gallon [UK] = 18.18436 Cups [Metric] There are 16 cups in a US fluid gallon, because from the largest to the smallest units from gallon to cup, there are 4 quarts in a gallon, 2 pints in a quart and 2 cups in each pint, that makes 4 * 2 * 2 = 16 cups in a gallon.
The imperial and the Canadian cups are no longer in use and replaced by metric cups (250 ml.). But if still needed, although their volume capacities are larger, there are also 16 imperial cups (284.131 ml) in an imperial gallon (4546.1 ml.), because 4546.1 (gal volume in ml.) / 284.131 (cup volume in ml.) = 16 imperial cups in an imperial (UK) gallon. The Canadian cup is 8 imperial fluid ounces or 227.3 ml. For example, to calculate how many cups of water or milk there are in a gallon and a half, multiply the gallon value by the conversion factor, 1.5 gal * 16 = 24 cups of water in a gallon and a half.
For US fluid gallons, there are 2 cups in 1/8 US gallon, 4 cups in a quarter (1/4) US gallon, 5.3 cups in 1/3 US gallon, 10.6 cups in 2/3 US gallon and 12 cups in 3/4 US gallon. For UK gallons, there are just about 2.3 cups in 1/8 UK gallon, 4.5 cups in a quarter (1/4) UK gallon, 6 cups in 1/3 UK gallon, 12 cups in 2/3 UK gallon and 13.5 cups in 3/4 UK gallon. Gallon is an imperial and US customary volume measurement unit. Imperial gallons are used for both fluid and dry volume measurement but US customary system have different gallons for dry and fluid volume measurements.
1 US fluid gallon is 3.785 liters, 1 US dry gallon is 4.4 liters and 1 imperial (UK) gallon is 4.546 liters. The abbreviation for gallon is "gal". Cup is a volume unit and used mostly to measure liquid and bulk, dry foods. There is no international standard for cups but mostly United States customary and metric cups are used. There are 16 cups in a US liquid gallon and about 18.5 cups in a US dry gallon. There are about 19.2 US cups or 18.2 metric cups in a UK gallon. The abbreviation for cup is "c".