How Many US Fluid Ounces in a US Gallon?

Quick Answer
1 US Gallon = 128 US Fluid Ounces

1 gal = 128 fl oz

Formula

fl oz = gal × 128

Conversion Table

US Gallons (gal)US Fluid Ounces (fl oz)
1 gal128 fl oz
2 gal256 fl oz
5 gal640 fl oz
10 gal1,280 fl oz
20 gal2,560 fl oz
50 gal6,400 fl oz
100 gal12,800 fl oz
500 gal64,000 fl oz
1,000 gal128,000 fl oz

Worked Examples

Convert 5 gal to fl oz:
5 gal × 128 = 640 fl oz
Convert 10 gal to fl oz:
10 gal × 128 = 1,280 fl oz
Convert 50 gal to fl oz:
50 gal × 128 = 6,400 fl oz

FAQ

How many US Fluid Ounces are in 1 US Gallon?
There are 128 US Fluid Ounces in 1 US Gallon. Formula: fl oz = gal × 128.
How to convert US Gallons to US Fluid Ounces?
To convert US Gallons to US Fluid Ounces, multiply the number of US Gallons by 128. For example, 10 gal = 1,280 fl oz.
How many US Fluid Ounces are in 100 US Gallons?
There are 12,800 US Fluid Ounces in 100 US Gallons. Calculation: 100 × 128 = 12,800.