Conversion formula

The conversion factor from gallons to cubic feet is 0.1336805555555, which means that 1 gallon is equal to 0.1336805555555 cubic feet:

1 gal = 0.1336805555555 ft3

To convert 138.5 gallons into cubic feet we have to multiply 138.5 by the conversion factor in order to get the volume amount from gallons to cubic feet. We can also form a simple proportion to calculate the result:

1 gal → 0.1336805555555 ft3

138.5 gal → V_(ft3)

Solve the above proportion to obtain the volume V in cubic feet:

V_(ft3) = 138.5 gal × 0.1336805555555 ft3

V_(ft3) = 18.514756944437 ft3

The final result is:

138.5 gal → 18.514756944437 ft3

We conclude that 138.5 gallons is equivalent to 18.514756944437 cubic feet:

138.5 gallons = 18.514756944437 cubic feet

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 cubic foot is equal to 0.054010970978502 × 138.5 gallons.

Another way is saying that 138.5 gallons is equal to 1 ÷ 0.054010970978502 cubic feet.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that one hundred thirty-eight point five gallons is approximately eighteen point five one five cubic feet:

138.5 gal ≅ 18.515 ft3

An alternative is also that one cubic foot is approximately zero point zero five four times one hundred thirty-eight point five gallons.

Conversion table

gallons to cubic feet chart

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