
Measurements & Conversions
How Many Ounces In A Gallon?
How Many Ounces In A Gallon — key numbers at a glance Quick answer 1 gallon equals 128 fluid ounces. Using USDA/FDA volume equivalents: 1 gallon = 16 cups, 1 cup = 8 fluid ounces, so 16 × 8 = 128 fluid ounces. How Many Ounces In A Gallon: 128 fluid ounces. In US kitchen