A gallon (3.8 quart) is equal to 44.5 fluid ounces (13.1L). The

4 US quarts A gallon (3.8 quart) is equal to 44.5 fluid ounces (13.1L). The proportion of each liquid quart in a gallon can vary depending on the type and size of container. For example, a 10 quart gallon has approximately 44.5 cups in it, while a 20 quart gallon typically has around 30.5 cups.