Conversion formula

The conversion factor from fluid ounces to gallons is 0.0078125, which means that 1 fluid ounce is equal to 0.0078125 gallons:

1 fl oz = 0.0078125 gal

To convert 398.4 fluid ounces into gallons we have to multiply 398.4 by the conversion factor in order to get the volume amount from fluid ounces to gallons. We can also form a simple proportion to calculate the result:

1 fl oz → 0.0078125 gal

398.4 fl oz → V_(gal)

Solve the above proportion to obtain the volume V in gallons:

V_(gal) = 398.4 fl oz × 0.0078125 gal

V_(gal) = 3.1125 gal

The final result is:

398.4 fl oz → 3.1125 gal

We conclude that 398.4 fluid ounces is equivalent to 3.1125 gallons:

398.4 fluid ounces = 3.1125 gallons

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 gallon is equal to 0.32128514056225 × 398.4 fluid ounces.

Another way is saying that 398.4 fluid ounces is equal to 1 ÷ 0.32128514056225 gallons.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that three hundred ninety-eight point four fluid ounces is approximately three point one one three gallons:

398.4 fl oz ≅ 3.113 gal

An alternative is also that one gallon is approximately zero point three two one times three hundred ninety-eight point four fluid ounces.

Conversion table

fluid ounces to gallons chart

For quick reference purposes, below is the conversion table you can use to convert from fluid ounces to gallons