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 639 fluid ounces into gallons we have to multiply 639 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

639 fl oz → V_(gal)

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

V_(gal) = 639 fl oz × 0.0078125 gal

V_(gal) = 4.9921875 gal

The final result is:

639 fl oz → 4.9921875 gal

We conclude that 639 fluid ounces is equivalent to 4.9921875 gallons:

639 fluid ounces = 4.9921875 gallons

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 gallon is equal to 0.20031298904538 × 639 fluid ounces.

Another way is saying that 639 fluid ounces is equal to 1 ÷ 0.20031298904538 gallons.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that six hundred thirty-nine fluid ounces is approximately four point nine nine two gallons:

639 fl oz ≅ 4.992 gal

An alternative is also that one gallon is approximately zero point two times six hundred thirty-nine 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