How Many Ounces in a Gallon (gal to oz)

How many ounces are in a gallon? Stop guessing and start measuring accurately with this helpful guide that also includes a conversion chart!

Have you ever found yourself in the middle of a recipe, needing to measure out an ingredient in ounces, but the recipe calls for gallons?

It can be confusing and frustrating but don't worry, you're not alone! Many people struggle with understanding how many ounces are in a gallon.

To make things even more complicated, the number of ounces in a gallon can vary depending on whether you're using the US or the Imperial measurement system.

In this blog post, we'll simplify conversions for ounces and gallons with easy-to-use charts, including helpful calculations, for confident cooking and baking.

📏 Units of measurement systems: US Customary, Imperial, and Metric

There are three main systems of units of measurement:

1. The US Customary system: It's used primarily in the United States and is based on the British Imperial system of units.
2. The Imperial system: It's used primarily in the United Kingdom and is also based on the British Imperial system of units.
3. The Metric system: It's used internationally and is based on the International System of Units (SI).

💧 What is a gallon?

A gallon is a unit of measurement for liquid capacity in both the US Customary and the British Imperial systems of measurement. The abbreviation for gallon is "gal."

In the US Customary system, a US liquid gallon is equivalent to 128 US fluid ounces or 3.785 liters, while in the UK Imperial system, an Imperial gallon is equal to 160 Imperial fluid ounces or 4.546 liters.

💦 What is a fluid ounce?

A fluid ounce is a unit of measurement for volume in both the US Customary and the UK Imperial systems of measurement. The abbreviation for fluid ounce is "fl oz".

In the US Customary system, one fluid ounce is equivalent to 1/128 of a gallon or 29.57 ml, while in the UK Imperial system, one fluid ounce is equal to 1/160 of a gallon or 28.41 ml.

🗺️ Measuring ounces and gallons internationally

As you have learned how to measure gallons in the United States, it is now time to explore how to measure them internationally.

The British Imperial system defines 1 UK gallon as equivalent to 1.2 US gallons or 160 Imperial fluid ounces.

Over time, the Imperial gallon underwent various changes, with its value ranging between 129 to 163 ounces.

In Canada, New Zealand, Australia, and South Africa, the metric system is more frequently used than Imperial gallons and ounces, while the US relies heavily on the Imperial system for most measurements.

🆚 Wet vs dry gallons

There are two types of gallons: wet gallons and dry gallons. Wet gallons are used to measure liquids, such as water, gasoline, and milk. One wet US gallon is equal to 128 US fluid ounces.

On the other hand, dry gallons are used to measure dry ingredients, such as grains, fruits, and vegetables. One dry gallon is equal to 231 cubic inches, which is equivalent to ⅛th of a bushel.

Although dry gallons are less commonly used than their liquid counterparts, it's important to note that a dry gallon is larger in size.

The conversion between dry and wet gallons remains the same, with 4 quarts in a gallon, 2 pints in a quart, and 2 cups in a pint, regardless of the type of ingredient being measured.

⚖️ Fluid vs dry ounces

Fluid ounces (fl oz) and dry ounces are both units of measurement for weight or volume, but they are not interchangeable.

Fluid ounces are used for liquids and are a measure of volume, while dry ounces are used for dry ingredients like grains and are a measure of weight.

One fluid ounce of water weighs one ounce, but the weight of a dry ounce can vary depending on the density of the material.

It's important to use the appropriate unit of measurement for the substance being measured.

💬 How many ounces are in a gallon?

In the US Customary system, there are 128 US fluid ounces in a US gallon, while in the UK Imperial system, there are 160 Imperial fluid ounces in an Imperial gallon.

So the number of ounces in a gallon depends on the specific measurement system being used.

✖️ How to convert gallons to ounces

🇺🇸 US Customary system

To convert US gallons to US fluid ounces, simply multiply the number of gallons by 128.

Here is a simple formula:

🇬🇧 UK Imperial system

To convert Imperial gallons to Imperial fluid ounces, simply multiply the number of gallons by 160.

Here is a simple formula:

📋 Fraction of gallon to US/Imperial fluid ounces conversion chart

This chart provides a simple guide to converting a fraction of a gallon to both US and Imperial fluid ounces, making it easy to calculate measurements for cooking and baking.

📋 Gallons to US/Imperial fluid ounces conversion chart

Here's a handy chart that you can use to convert gallons to either US or Imperial fluid ounces.

💬 How many gallons are in an ounce?

In the US Customary system, there are approximately 0.0078125 US gallons in one fluid ounce, while in the UK Imperial system, a fluid ounce equals 0.00625 Imperial gallons.

➗ How to convert ounces to gallons

🇺🇸 US Customary system

To convert US fluid ounces to US gallons, simply divide the number of fluid ounces by 128.

Here is a simple formula:

🇬🇧 UK imperial system

To convert Imperial fluid ounces to Imperial gallons, simply divide the number of fluid ounces by 160.

Here is a simple formula:

📋 Fluid ounces to US/Imperial gallons conversion chart

Here is a straightforward conversion chart for liquid measurements, which shows how to convert fluid ounces to both US and Imperial gallons for convenient reference.

📋 Quick conversion chart

Here is a quick and handy conversion chart for your convenience that is useful for converting smaller amounts into gallons.

💭 More conversion guides

• How Many Grams in an Ounce (oz to g)
• How Many Tablespoons in a Cup (tbsp to cup)