# How Many Ounces in a Gallon

Here’s everything you need to know about how to convert ounces to gallons (oz to gal or gal to oz). How many ounces in a gallon (how many oz in a gallon) and how many fluid ounces in a gallon? What is an ounce and what is a gallon? I’ve also provided you with an easy conversion chart below to help you memorize these conversions.

Being successful in the kitchen requires the accurate measurement of ingredients. When following recipes to make a meal, you might be able to eyeball the amount of herbs and spices and other simple ingredients, but if you add too much or too little of an ingredient, the outcome of your recipe might not be what you had hoped for. Knowing how many oz in a gallon is a helpful liquid measurement conversion to have memorized for achieving success in the kitchen.

## How Many Ounces Are In A Gallon (How Many Oz In A Gallon)

The answer to this will depend on whether you’re measuring wet or dry ingredients and the system (US Customary or Imperial) used to measure.

In the United States 1 dry gallon equals 148.94545 ounces, 1 liquid gallon equals 128 fluid ounces and 1/2 liquid gallon equals 64 fluid ounces.

## How Many Fluid Ounces in a Gallon

It’s helpful to know some simple kitchen conversions when you’re needing to adjust a recipe whether its to double it or cut the amount in half. Knowing these simple conversions will help you adjust measurements in a recipe so you can achieve the desired serving size.

**In the United States 128 fluid ounces equals 1 gallon**

1 gallon = 128 fluid ounces

3/4 gallon = 96 fluid ounces

1/2 gallon = 64 fluid ounces

1/4 gallon = 32 fluid ounces

**In the United Kingdom 160 fluid ounces equals 1 gallon**

1 gallon = 160 fluid ounces = 4.732 liters

## Liquid Measurement Chart

These are some basic U.S. liquid measurement conversions that are good know, especially if you spend a lot of time in the kitchen.

## How To Covert Ounces To Gallons

Want to know How Many Oz in a Gallon? Here’s an easy conversion formula.

Take the ounce value and divide it by 128 [128 = the number of ounces in 1 gallon]

Ounce value ÷ 128 = # of gallons

**Example – US Customary**

64 oz ÷ 128 = 0.5 [64 oz ÷ 128 = 1/2 gallon]

32 oz ÷ 128 = 0.25 [32 oz ÷ 128 = 1/4 gallon]

16 oz ÷ 128 = 0.125 [16 oz ÷ 128 = 1/8 gallon]

8 oz ÷ 128 = 0.0625 [8 oz ÷ 128 = 1/16 gallon]

## What is an Ounce

Ounce is used to measure the “weight” of something (like flour and sugar). The word “ounce” comes from the Latin word “unica” meaning “one-twelfth” and it was abbreviated as “oz” back in the 1500s. The abbreviation “oz” comes from the Italian word “onza”, which also means “ounce”.

## What is a Fluid Ounce

“Fluid ounce” (fl oz or fl. oz.) is from the Imperial and U.S. Customary System measurements system that is used in the measurement of the volume of liquid ingredients (like milk, water or juice). The term fluid ounce is often abbreviated as fl. oz or fl oz, which means either a single fluid ounce or fluid ounces (both “ounce” and “ounces” can be abbreviated as “oz”).

Fluid ounces are still used in the United States Customary System of measurements, while the United Kingdom stopped using this legal unit of measure and started using the Metric System in 2000

## Wet vs Dry

It’s important to remember that wet and dry ingredients have different densities (solids are more dense than liquids) so they need to be measured differently. When cooking, remember to keep in mind that there are different types of ounces – fluid ounces (fl oz) and dry ounces (oz). Fluid ounces measures the volume of the liquid and dry ounces measures the weight of the ingredient. If your recipe calls for your ingredients in measurements in ounces or pounds (such as flour, chocolate chips or nuts), you would need to use a kitchen scale to measure the exact weight of the ingredient. To measure fluid ounces, you would use a liquid measuring cup.

## What is a Gallon

In the U.S. a Gallon (abbreviated “gal”) is a measurement in the Imperial and United States customary measurement systems used to measure volume or how much liquid a container can hold. A gallon is a unit of volume equal to 4 quarts, 8 pints, 16 cups and 128 fluid ounces, but the British imperial gallon is about 20% larger than the U.S. gallon because the two measuring systems are defined differently. Most other countries have standardized their measurements to the metric system.

## Imperial (US) System vs Metric System

Different countries use different volume and weight measurements. Some countries use the Imperial System while some use the Metric System.

The United States still uses the Imperial System for measurements, where most countries like the United Kingdom, Australia, Canada have adopted the metric system using measurements like grams, meters, liters, kilograms and kilometers. There aren’t significant differences in volume between the Imperial (US) and Metric measuring systems. You can easily use US teaspoons and tablespoons for metric measurements if a recipe is written using the Metric system. The Imperial system of units was developed and used in the United Kingdom around 1826.

For the most part, the Metric System has replaced the imperial system in countries who once used it. The United States is one of the few countries in the world who has yet to switch to the Metric System of measurements.

## The US Customary System

The United States Customary System (U.S. Customary System) is a system of weights and measures used in the United States and some other countries. This system includes units for measuring length (inches, feet, yards and miles), weight (ounce, pound, ton), and capacity (teaspoons, tablespoon, cups, pints, quarts and gallons).

## Conclusion – How Many Oz In A Gallon

**How many ounces in a gallon?**

1 gallon = 128 fluid ounces

**How many ounces in 1/2 a gallon?**

1 gallon = 64 fluid ounces

**How many ounces in a gallon of water?**

In the US 1 gallon of water = 128 fluid ounces