Conversion formula

The conversion factor from cubic feet to gallons is 7.4805194805226, which means that 1 cubic foot is equal to 7.4805194805226 gallons:

1 ft3 = 7.4805194805226 gal

To convert 21 cubic feet into gallons we have to multiply 21 by the conversion factor in order to get the volume amount from cubic feet to gallons. We can also form a simple proportion to calculate the result:

1 ft3 → 7.4805194805226 gal

21 ft3 → V_(gal)

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

V_(gal) = 21 ft3 × 7.4805194805226 gal

V_(gal) = 157.09090909097 gal

The final result is:

21 ft3 → 157.09090909097 gal

We conclude that 21 cubic feet is equivalent to 157.09090909097 gallons:

21 cubic feet = 157.09090909097 gallons

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 gallon is equal to 0.0063657407407381 × 21 cubic feet.

Another way is saying that 21 cubic feet is equal to 1 ÷ 0.0063657407407381 gallons.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that twenty-one cubic feet is approximately one hundred fifty-seven point zero nine one gallons:

21 ft3 ≅ 157.091 gal

An alternative is also that one gallon is approximately zero point zero zero six times twenty-one cubic feet.

Conversion table

cubic feet to gallons chart

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