**Gallons to ounces** conversion factors are listed below (for US, UK and for both fluid and dry measurements). To find out how many ounces in a gallon, multiply by the conversion factors or instead, use the converter if the conversion is from US fluid gallons into US fluid ounces. **If scroll down**, you may also create and print your own custom conversion table create your table.

**1 Gallon [Fluid, US] = 128 Ounces [Fluid, US]**

**1 Gallon [Dry, US] = 148.94684 Ounces [Fluid, US]**

**1 Gallon [UK] = 160 Ounces [UK]**

For example, to find out how many ounces there are in a half (1/2) gallon, multiply the gallon value by the conversion factor, (1/2) * 128 = 64 fl. ounces.

For **US fluid gallons**, there are 16 oz in 1/8 US gallon, 32 oz in a quarter (1/4) US gallon, 42.6 oz in 1/3 US gallon, 85.3 oz in 2/3 US gallon and 96 oz in 3/4 US gallon.

For **UK gallons**, there are 20 oz in 1/8 UK gallon, 40 oz in a quarter (1/4) UK gallon, 53.3 oz in 1/3 UK gallon, 106.6 oz in 2/3 UK gallon and 120 oz in 3/4 UK gallon.

**Gallon** is unit of volume in imperial and U.S. customary systems. An **imperial gallon is officially defined as** equal in volume to 10 avoirdupois pounds (4.53 kg) of distilled water weighed at 62 degrees Fahrenheit (16.66 degrees Celsius) with barometer at 30 inches or equal to 277.421 cubic inches. The **U.S. gallon is defined as** 231 cubic inches or 8.3389 avoirdupois pounds (3.78 kg) of distilled water at its maximum density, and with the barometer at 30 inches. Gallon is the **largest unit of volume** in U.S. customary and imperial measurement systems. The imperial gallon is 17% larger than the U.S. gallon.

After the metric system is adapted, it is replaced with the liter (litre) which is a SI accepted volume unit in metric system. In U.S. customary system, there are two types of gallons (fluid and dry) and they are different in sizes, in imperial system there is only one type of gallon. The abbreviation is "**gal**".

**Fluid ounce** is an imperial and U.S. customary measurement system volume unit. Fluid ounce is the **smallest unit of volume** in imperial and U.S. customary systems. U.K. fluid ounce equals to one twentieth of a pint and U.S. fluid ounce equals to one sixteenth of a U.S. pint. Fluid ounces are different than the ounces (oz) which is a mass (weight) unit. The abbreviation is "**fl oz**".