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.

## Jump to:

- 📏 Units of measurement systems: US Customary, Imperial, and Metric
- 💧 What is a gallon?
- 💦 What is a fluid ounce?
- 🗺️ Measuring ounces and gallons internationally
- 🆚 Wet vs dry gallons
- ⚖️ Fluid vs dry ounces
- 💬 How many ounces are in a gallon?
- ✖️ How to convert gallons to ounces
- 📋 Fraction of gallon to US/Imperial fluid ounces conversion chart
- 📋 Gallons to US/Imperial fluid ounces conversion chart
- 💬 How many gallons are in an ounce?
- ➗ How to convert ounces to gallons
- 📋 Fluid ounces to US/Imperial gallons conversion chart
- 📋 Quick conversion chart
- ❓FAQs
- 🌟 Conclusions
- 💭 More conversion guides

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

There are three main systems of units of measurement:

**The US Customary system**: It's used primarily in the United States and is based on the British Imperial system of units.**The Imperial system**: It's used primarily in the United Kingdom and is also based on the British Imperial system of units.**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:

Number of fluid ounces = number of gallons x 128

### 🇬🇧 UK Imperial system

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

Here is a simple formula:

Number of fluid ounces = number of gallons x 160

## 📋 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 | US fluid ounces | Imperial fluid ounces |

1 gal | 128 fl oz | 160 fl oz |

¾ gal | 96 fl oz | 120 fl oz |

⅔ gal | 85 fl oz | 107 fl oz |

½ gal | 64 fl oz | 80 fl oz |

⅓ gal | 42 fl oz | 53 fl oz |

¼ gal | 32 fl oz | 40 fl oz |

⅛ gal | 16 fl oz | 20 fl oz |

1/16 gal | 8 fl oz | 10 fl oz |

## 📋 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.

Gallons | US fluid ounces | Imperial fluid ounces |

1 gal | 128 fl oz | 160 fl oz |

2 gal | 256 fl oz | 320 fl oz |

3 gal | 384 fl oz | 480 fl oz |

4 gal | 512 fl oz | 640 fl oz |

5 gal | 640 fl oz | 800 fl oz |

6 gal | 768 fl oz | 960 fl oz |

7 gal | 896 fl oz | 1,120 fl oz |

8 gal | 1,024 fl oz | 1,280 fl oz |

9 gal | 1,152 fl oz | 1,440 fl oz |

10 gal | 1,280 fl oz | 1,600 fl oz |

20 gal | 2,560 fl oz | 3,200 fl oz |

30 gal | 3,840 fl oz | 4,800 fl oz |

40 gal | 5,120 fl oz | 6,400 fl oz |

50 gal | 6,400 fl oz | 8,000 fl oz |

100 gal | 12,800 fl oz | 16,000 fl oz |

## 💬 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:

Number of gallons = number of fluid ounces / 128

### 🇬🇧 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:

Number of gallons = number of fluid ounces / 160

## 📋 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.

Fluid ounces | US gallons | Imperial gallons |

1 fl oz | 0.0078125 gal | 0.00650526 gal |

2 fl oz | 0.015625 gal | 0.0130105 gal |

3 fl oz | 0.0234375 gal | 0.0195158 gal |

4 fl oz | 0.03125 gal | 0.0260210 gal |

5 fl oz | 0.0390625 gal | 0.0325263 gal |

6 fl oz | 0.046875 gal | 0.0390316 gal |

7 fl oz | 0.0546875 gal | 0.0455368 gal |

8 fl oz | 0.0625 gal | 0.0520421 gal |

9 fl oz | 0.0703125 gal | 0.0585474 gal |

10 fl oz | 0.078125 gal | 0.0650526 gal |

20 fl oz | 0.15625 gal | 0.125 gal |

30 fl oz | 0.234375 gal | 0.1875 gal |

40 fl oz | 0.3125 gal | 0.25 gal |

50 fl oz | 0.390625 gal | 0.3125 gal |

60 fl oz | 0.46875 gal | 0.375 gal |

70 fl oz | 0.546875 gal | 0.4375 gal |

80 fl oz | 0.625 gal | 0.5 gal |

90 fl oz | 0.703125 gal | 0.5625 gal |

100 fl oz | 0.78125 gal | 0.625 gal |

1000 fl oz | 7.8125 gal | 6.25 gal |

## 📋 Quick conversion chart

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

Gallons | Quarts | Pints | Cups | US fl oz | UK fl oz |

1 gal | 4 qt | 8 pt | 16 c | 128 fl oz | 160 fl oz |

½ gal | 2 qt | 4 pt | 8 c | 64 fl oz | 80 fl oz |

¼ gal | 1 qt | 2 pt | 4 c | 32 fl oz | 40 fl oz |

⅛ gal | ½ qt | 1 pt | 2 c | 16 fl oz | 20 fl oz |

1/16 gal | ¼ qt | ½ pt | 1 c | 8 fl oz | 10 fl oz |

1/32 gal | ⅛ qt | ¼ pt | ½ c | 4 fl oz | 5 fl oz |

1/64 gal | 1/16 qt | ⅛ pt | ¼ c | 2 fl oz | 2.5 fl oz |

## ❓FAQs

**How many ounces in a half gallon?**

In the US, a half gallon is equal to 64 US fluid ounces, while in the UK, a half gallon is equal to 80 Imperial fluid ounces.

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

In the US, there are 128 US fluid ounces in one gallon of water, while in the UK, there are 160 Imperial fluid ounces in one gallon of water.

Knowing the number of fluid ounces in a gallon can be helpful if you are trying to meet the recommended daily water intake.

The recommended daily fluid intake may vary depending on the source, but the National Academy of Medicine suggests the following amounts:

- **Men: **104 ounces (13 US cups, 0.8125 US gallons, or 3.076 liters).

- **Women: **72 ounces (9 US cups, 0.5625 US gallons, or 2.129 liters).

Other factors that may affect how much water a person needs include physical activity level, body size, exposure to extreme climates, illness, alcohol use, and certain medications, among others.

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

There are approximately 16 eight-ounce glasses of water in a US gallon.

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

In the US, there are 128 fluid ounces in a gallon of milk. In the UK, there are 160 fluid ounces in an imperial gallon of milk.

Look at my non-dairy milk guide for delicious and healthy plant-based milk recipes!

**How many ounces in a gallon of ice cream?**

There are 128 fluid ounces in a US gallon of ice cream, and 160 fluid ounces in an Imperial (UK) gallon of ice cream.

Try my vegan ice cream recipe for a healthier and plant-based alternative to regular ice cream!

## 🌟 Conclusions

**A gallon is a unit of measurement for liquid capacity**in both the US Customary and the British Imperial systems.**One US gallon equals 128 fluid ounces**or 3.785 liters, while one Imperial gallon is equal to 160 fluid ounces or 4.546 liters.**Fluid ounces are used for liquids and measuring volume**, while dry ounces are used for dry goods and measuring weight.- There are
**wet gallons**for liquids and**dry gallons**for dry ingredients. - It's important to
**use the appropriate units of measurement**and be aware of variations between countries.

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