How Many Oz in a Gallon
128 fluid ounces = 1 gallon — complete breakdown
⚡Quick Answer
1 US gallon = 128 fl oz. Half gallon = 64 oz. Quarter gallon = 32 oz. UK gallon = 160 oz (different!).
Step-by-Step Guide
The Quick Answer
1 US gallon = 128 fluid ounces. This is the standard for US liquid measurements.
Easy Breakdown
1 gallon = 128 oz = 4 quarts = 8 pints = 16 cups. Each quart = 32 oz. Each pint = 16 oz. Each cup = 8 oz.
Common Conversions
1 gallon = 128 oz | ½ gallon = 64 oz | ¼ gallon = 32 oz | 1 quart = 32 oz | 1 pint = 16 oz | 1 cup = 8 oz
UK vs US Gallon
US gallon = 128 fl oz. UK gallon = 160 fl oz (UK oz are smaller). Don't mix them up!
Frequently Asked Questions
How many 8 oz glasses in a gallon?
16 glasses. 128 ÷ 8 = 16. This is where the '8 glasses a day' recommendation comes from (half gallon).
How many 16 oz bottles in a gallon?
8 bottles. 128 ÷ 16 = 8. Standard water bottles are often 16.9 oz, so about 7.5 bottles per gallon.
How many ounces in a half gallon?
64 fluid ounces. Half of 128 = 64 oz = 2 quarts.