How many fluid ounces are in 1 gallon

Wondering how many ounces are in a gallon, half a gallon, quart, pint, or cup? We often forget too and have to look this up. Here are all the answers you need to when measuring volume, and handy printable cheat sheets to keep on hand for the next time.

Let’s get started—here are common conversions for fluid ounces using the US measurement system.

128 ounces = 1 gallon

There are 128 fluid ounces in a gallon.

How Many Ounces in a Half Gallon?

64 ounces = 1/2 gallon

There are 64 fluid ounces in a half-gallon.

How Many Ounces in a Quart?

32 ounces = 1 quart

There are 32 fluid ounces in a quart.

How Many Ounces in a Pint?

16 ounces = 1 pint

There are 16 fluid ounces in a pint.

How Many Ounces in a Cup?

8 ounces = 1 cup

There are 8 fluid ounces in a cup.

Free Printable Cheat Sheets

Download these free printable kitchen measurement charts (including fluid ounce conversions!) to keep on hand for easy reference. They’re a great visual—you can even take screenshots and keep them in the photo section of your phone for easy referencing.

Sign up for this Subscriber Exclusive Freebie. You’ll get these awesome free charts as a thank you for joining our email list. Please note you’ll get an email asking you to confirm & once you confirm, you’ll receive a separate email with the freebie.

Kitchen Conversions Magnets

Want something more convenient than a printable? Check out our kitchen measurement magnets, in three unique designs, so you will always have an easy way to reference common cooking conversions.

Fluid Ounces Measurement Conversions

The US System uses teaspoons, tablespoons, cups, pints, quarts, gallons, and fluid ounces to measure volume. Here are the primary measurement conversions for each.

Ounces (or fl. oz.)

1 fluid ounce = 2 tablespoons = 6 teaspoons = 1/8 cup

One fluid ounce is equal to 2 tablespoons or 1/8 cup.

Teaspoons (or tsp.)

6 teaspoons = 2 tablespoons = 1 fluid ounce

There are 6 teaspoons in a fluid ounce.

Tablespoons (or tbsp.)

2 tablespoons = 1 fluid ounce

There are 2 tablespoons in a fluid ounce.

Cups (or c.)

1 cup = 8 fluid ounces

There are 8 fluid ounces in a cup.

Pint (or pt.)

1 pint = 16 fluid ounces = 2 cups = 1/2 quart = 1/8 gallon

There are 16 fluid ounces in 1 pint.

Quart (or qt.)

1 quart = 32 fluid ounces = 4 cups = 1/4 gallon

There are 32 fluid ounces in a quart.

Gallon (or gal.)

1 gallon = 128 fluid ounces = 16 cups = 8 pints = 4 quarts

There are 128 fluid ounces in a gallon.

Convert Ounces Using Liquid Measuring Cups

A convenient way to measure and convert fluid ounces to cups, pints, quarts, or gallons is to use liquid measuring cups.

You can find a variety of sizes like this set of liquid measuring cups. We love the angled sides to more accurately measure.

1. Large Measuring Cup: 32 fluid ounces = 4 cups, 1 quart, 1/4 gallon
2. Medium Measuring Cup: 16 fluid ounces = 2 cups, 1/2 quart, 1/8 gallon
3. Small Measuring Cup: 8 fluid ounces = 1 cup

You can also find mini liquid measuring cups: 2 ounces = 1/4 cup, 4 tablespoons

A small medicine cup will typically measure in milliliters (ml) and teaspoons (tsp).

Related Questions

Here are answers to common questions about measuring liquids in fluid ounces. Including conversions for specific liquids like water and milk.

How many ounces in a gallon of water?

There are 128 fluid ounces in a gallon of water.

128 fl. oz. = 1 gallon of water

How many ounces are in a gallon of milk?

There are 128 fluid ounces in a gallon of milk.

128 fl. oz. = 1 gallon of milk

How many ounces are in a gallon of ice cream?

There are 128 fluid ounces in a gallon of ice cream, and 64 ounces in a half-gallon of ice cream. No matter what volume is being measured, there will always be 128 fluid ounces in a gallon.

How many 20 ounces are in a gallon?

There are 6.4 20-ounces in a gallon or 128 fluid ounces.

6.4 x 20 fl. oz. = 128 fl. oz. in one gallon

How many 16.9-ounce bottles are in a gallon?

You will need 7.574 16.9-ounce bottles to make one gallon or 128 fluid ounces.

7.574 x 16.9 fl. oz. = 128 fl. oz. in one gallon

How many 16 ounces are in a gallon?

There are 8 16-ounces in a gallon.

8 x 16 fl. oz. = 128 fl. oz. in a gallon.

How many 12 ounces are in a gallon?

You will need 10.6667 twelve-ounce measurements to make one gallon or 128 fluid ounces.

10.6667 x 12 fl. oz. = 128 fl. oz. in a gallon.

How many quarts in a liter?

There are 1.06 quarts in a liter (metric system).

0.95 Quarts (US Measurement System) = 1 Liter (Metric System)

How many 8 oz glasses does it take to make a gallon?

It takes sixteen 8-ounce glasses to make a gallon.

8 fl. oz. x 16 = 128 fl. oz. in a gallon.

How are the US System, British Imperial System, and Metric System different when measuring volume?

The US Customary System, which is the measurement basis for this article, uses fluid ounces as well as cups, pints, quarts, and gallons when measuring volume.

The British Imperial System (also known as the UK Imperial System) also uses fluid ounces (you may hear mention of imperial fluid ounces or imperial gallons); however, the conversion differs slightly from the US system and they don’t use cups at all.

Another system of measuring liquid or volume is the Metric (SI) System, which uses liters as the base units. One liter is equivalent to about 33.814 US fluid ounces.

Final Thoughts

Now that you know how many fluid ounces are in a gallon, it’s time to put your knowledge into practice. Be sure to sign up for our free cheat sheets so you have them on hand for the next time you need to convert ounces to gallons (or cups, pints, or quarts).

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How Many Ounces in a Gallon? + Free Cheat Sheets!