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Gallons to oz Converter (US Gallons to US Fluid Ounces)

1 US gallon = 128 US fluid ounces. To convert gal to fl oz, multiply by 128.

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1 gal = 128 fl oz

1 gal
128 fl oz
1 fl oz
0.007813 gal
10 gal
1,280 fl oz
100 gal
12,800 fl oz

How to convert Gallons to oz

1 US gallon equals 128 US fluid ounces, so the conversion is a single multiplication.

fl oz = gal × 128

Example: 2 gal × 128 = 256 fl oz.

About the US gallon and the US fluid ounce

US Gallon (gal)

The US gallon is defined as 231 cubic inches, exactly 3.785411784 liters. It's about 17% smaller than the imperial (UK) gallon.

US Fluid Ounce (fl oz)

The US fluid ounce is 1/128 of a US gallon, about 29.57 mL. It's a volume unit, not a weight.

1 US gallon in every volume unit

Milliliters3,785.412 mL
US Fluid Ounces128 fl ozLiters3.785 L
US Cups16 cup
Tablespoons256 tbsp
Teaspoons768 tsp
US Quarts4 qt
US Pints8 pt
Imperial Gallons0.8327 imp gal
Imperial Quarts3.331 imp qt
Imperial Pints6.661 imp pt
Imperial Fluid Ounces133.228 imp fl oz
Metric Cups15.142 metric cup
Deciliters37.854 dL
Centiliters378.541 cL
Cubic Meters0.003785 m³
Cubic Centimeters3,785.412 cm³
Cubic Feet0.1337 ft³
Cubic Inches231 in³
Cubic Yards0.004951 yd³
Oil Barrels0.02381 bbl
Acre-Feet0.000003069 ac·ft
US Bushels0.1074 bu
US Pecks0.4297 pk
US Dry Pints6.875 dry pt
oz to GallonsReverse conversionml to oz1 mL = 0.03381 fl ozoz to ml1 fl oz = 29.5735 mLLiters to Gallons1 L = 0.2642 galGallons to Liters1 gal = 3.7854 LCups to oz1 cup = 8 fl ozoz to Cups1 fl oz = 0.125 cupQuarts to Gallons1 qt = 0.25 galGallons to Quarts1 gal = 4 qtLiters to oz1 L = 33.814 fl ozoz to Liters1 fl oz = 0.02957 LCubic Feet to Gallons1 ft³ = 7.4805 gal

Quick answers

How many ounces in a cup?8 US fluid ouncesHow many cups in a quart?4 US cupsHow many teaspoons in a tablespoon?3 teaspoonsHow many ounces in a gallon?128 US fluid ouncesHow many liters in a gallon?3.785 litersHow many quarts in a gallon?4 US quartsHow many tablespoons in 1/4 cup?4 tablespoons

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Gallons to oz FAQ

How many US fluid ounces are in a US gallon?

1 US gallon = 128 US fluid ounces.

How many US gallons are in a US fluid ounce?

1 US fluid ounce = 0.0078125 US gallons.

How do I convert gal to fl oz?

Use fl oz = gal × 128. For example, 10 gal = 1,280 fl oz.

Can I print this Gallons to oz chart?

Yes. Use "Print / Save PDF" next to the converter for a one-page chart, or "Download CSV" to open it in Excel or Google Sheets.