For other volume unit conversions, please go to Volume Conversion. The conversion factor from gallons to quarts for both fluid and dry volume measurement is 4 (gallon is 4 times larger than quart). To find out how many quarts in gallons, simply multiply by 4 or use the converter below. 1 Gallon = 4 Quarts [US, UK, fluid or dry]. Gallon and quart are volume measurement units in imperial and US customary systems. There are fluid and dry measurement for both units in US customary but in not imperial system.