### Quick Answer

**There are 128 fluid ounces in 1 gallon.** It’s important to know the different liquid measurement conversion factors that relate ounces, quarts, cups and gallons.

### Full Answer

Using a conversion table to find the volume of liquids, a person can calculate the answer by utilizing the facts that 1 quart equals 32 fluid ounces and 4 quarts equals 1 gallon. It’s simple to find the answer by multiplying 4 by 32 to get 128 ounces.

An alternate way of calculating this is to use equivalent measurements for cups, fluid ounces and gallons. Because 1 cup equals 8 fluid ounces and 16 cups is equivalent to 1 gallon, then the answer is 8 multiplied by 16, which also gives 128 ounces.