Convert one gallon (US) to fluid ounces (US)

Explanation

To convert one gallon (US) to fluid ounces (US) all we need is to know the conversion factor and we are done. Luckily, we can compute that factor using the units' definitions below.

The result is that there are 128 fluid ounces (US) in 1 gallon (US).

Formula

1 gal = 128 fl oz

gallons (US)gal

dimension	volume
system	U.S. customary units (USCS)
symbol	gal

The gallon (gal) is a unit of volume in the U.S. customary units.

Definition of the gallon

One gallon is equal to 231 cubic inches.

NIST Handbook 44 Specifications: Appendix C p. C-5

Value in terms of the SI

One gallon is equivalent to 3785.411784 cubic centimeters.

Equivalences

One US gallon is also equivalent to:

Some Facts

In the US, oil (petroleum) is priced per gallon. We also have to mention the very famous gallon of milk. In the rest of the world, the liter is prefered for the same usage.

US fluid volume units

minim	min
fluid dram	fl dr	60 minims
fluid ounce	fl oz	8 fluid drams
gill	gi	4 fluid ounces
pint	pt	4 gills
quart	qt	2 pints
gallon	gal	4 quarts
barrel	bbl	31.5 gallons
barrel (petroleum)	bbl	42 gallons

The United States Customary System

The United States customary system is a system of measurements used in the United States since 1832. It is based on English units in use before the definition of the Imperial system in 1824.

With the Metric Conversion Act of 1975 the U.S. began a metrication program but customary units are still widely used.

fluid ounces (US)fl oz

dimension	volume
system	U.S. customary units (USCS)
symbol	fl oz, floz

The fluid ounce (fl oz, floz) is a unit of volume in the U.S. customary units.

Definition of the fluid ounce

There are 128 US fluid ounces in one US gallon.