This post may contain affiliate links. See my disclosure policy.
Looking for an answer to how many ounces are in a gallon? This easy conversion chart will break it all down for you and make kitchen measurements a breeze!
It’s important to know the difference between different units of measurement. You might be in the middle of following a recipe, doing a project, or needing to measure something and needing it to be accurate and complete.
This often happens when we need to work out how many ounces are in a gallon or vice versa. Instead of racking your brain and trying to figure this out using complex mathematics, you can follow a simple method to do so.
Also, the number of ounces in a can differ depending on which county you reside in. Luckily, we clear all of that up for you and discuss different ways of measuring gallons around the world.
Table of Contents
What is a gallon?
A gallon is a unit of volume in both the Imperial and U.S. customary systems and is a unit of capacity for liquid volume. The abbreviation for gallon is “gal,” and it’s different from ounces.
How many ounces are in a gallon?
There are 128 fluid ounces in a gallon.
However, it can vary depending upon liquid or dry gallons and the system of units used. In dry US gallons, there are 148.94545 ounces.
If you use the British Imperial system, then there are 153 fluid ounces in 1 Imperial gallon.
An important thing to note is that the United Kingdom only uses the British Imperial system for gallons. For almost all other measurements, they use the metric system (like measuring how many ounces are in a cup).
Ounces to gallons conversion
The formulas for converting ounces to gallons differ if you’re using the British or US customary system. The following conversion formula is useful if you have US units.
Metric conversion = fluid ounces ÷ 128
If you are dealing with the Imperial conversion system, the following formula will be used to find gallons:
Imperial conversion = fluid ounces ÷ 153
Here is a quick conversion chart for your convenience:
| 8 fl oz | 1/16 gallon |
| 16 fl oz | ⅛ gallon |
| 32 fl oz | ¼ gallon |
| 64 fl oz | ½ gallon |
| 128 fl oz | 1 gallon |
Measuring ounces and gallons internationally
Now that you know how to measure gallons in the United States, let’s see how to measure it internationally.
Using the British Imperial system, 1 UK gallon equals 1.2 US gallons or 153.6 fluid ounces. Many changes have occurred in the Imperial gallon over time, and the value was changed anywhere between 129 to 163 ounces.
In Canada, New Zealand, Australia and South Africa, the metric system is more common than Imperial gallons and ounces. In the United States, the Imperial system is used for almost everything.
Wet vs dry gallons
Wet vs dry gallons aren’t the same and you need to know the difference.
A dry gallon equals ⅛ of a bushel or 231 cubic inches. A dry gallon isn’t used as often as a liquid gallon and is larger in size. The general conversion is the same for both dry and wet gallons and you get 4 quarts in a gallon, 2 pints in a quart, and 2 cups in a pint.
More measurement resources
- How many cups in a quart
- How many teaspoons in a tablespoon
- How many tablespoons in a cup
- Ounces in a cup
- How many quarts in a gallon
Frequently Asked Questions
No, 1 gallon isn’t the same as 64 ounces because there are 128 ounces in 1 gallon.
A gallon of water is equal to 128 fluid ounces.
Eight 16 oz bottles of water will be equal to a gallon.
There are 0.25 gallons in 32 ounces.
Yes, 128 ounces make 1 gallon, so they are the same.
There are 64 fluid ounces in a half gallon.
A quarter gallon contains 32 fluid ounces.
