# How Many Ounces are in a Gallon?

Last Updated : 01 Feb, 2024

Converting between ounces and gallons is a fundamental aspect of volume measurement, especially in contexts where both the imperial and US customary systems are used.

## Answer: There are 128 ounces in a US gallon.

This conversion is based on the US liquid measurement system:

• 1 US Gallon:
• A US gallon is a unit of volume in the US customary and imperial systems of measurement.
• It is used primarily in the United States.
• 1 Ounce:
• An ounce, specifically a fluid ounce in this context, is another unit of volume.
• It is smaller than a gallon and commonly used for smaller quantities of liquids.
• Conversion:
• There are exactly 128 US fluid ounces in one US gallon.
• This means to find out how many ounces are in a gallon, you multiply the number of gallons by 128.

### One Gallon is equal to 128 ounces.

It’s important to note that these measurements are specific to the US system. The UK gallon, used in the British imperial system, is different, where 1 UK gallon equals 160 UK fluid ounces.