How many US fluid ounces are in one US gallon?

One US gallon equals 128 fl oz. The formula is fl oz = gal × 128.

How do I convert US gallons to US fluid ounces?

Multiply the value in US gallons by 128. For example, 100 × 128 = 12,800 — so 100 gal = 12,800 fl oz.

How many US gallons are in one US fluid ounce?

One US fluid ounce equals 0.007813 gal.

Pair · linear · factor 128

US gallons to US fluid ounces

galfl oz

Active unit

US gallons · ≈ 378.54 l (base)

All units

7 results

Click to activate · Ctrl-click to set target

galUS gallon100

How we calculated this

Target:

Frequently asked questions

Two glowing graduated measuring jugs of visibly different size — the smaller emerald, the larger violet-magenta — against a cosmic nebula and scattered stars

Volume

US vs imperial gallon — where the 20% comes from

Three gallons in one kingdom, wine against grain, a government that raised fuel duty without touching the rate, and British cars that "burn less" than identical American ones. Two gallons differ by a fifth — enough to ruin every fuel-price comparison, every recipe, and every economy figure.

10 min