Conversion formula

The conversion factor from cups to gallons is 0.0625, which means that 1 cup is equal to 0.0625 gallons:

1 cup = 0.0625 gal

To convert 643.5 cups into gallons we have to multiply 643.5 by the conversion factor in order to get the volume amount from cups to gallons. We can also form a simple proportion to calculate the result:

1 cup → 0.0625 gal

643.5 cup → V_(gal)

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

V_(gal) = 643.5 cup × 0.0625 gal

V_(gal) = 40.21875 gal

The final result is:

643.5 cup → 40.21875 gal

We conclude that 643.5 cups is equivalent to 40.21875 gallons:

643.5 cups = 40.21875 gallons

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 gallon is equal to 0.024864024864025 × 643.5 cups.

Another way is saying that 643.5 cups is equal to 1 ÷ 0.024864024864025 gallons.

Approximate result

For practical purposes we can round our final result to an approximate numerical value. We can say that six hundred forty-three point five cups is approximately forty point two one nine gallons:

643.5 cup ≅ 40.219 gal

An alternative is also that one gallon is approximately zero point zero two five times six hundred forty-three point five cups.

Conversion table

cups to gallons chart

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