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 640.4 cups into gallons we have to multiply 640.4 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

640.4 cup → V_(gal)

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

V_(gal) = 640.4 cup × 0.0625 gal

V_(gal) = 40.025 gal

The final result is:

640.4 cup → 40.025 gal

We conclude that 640.4 cups is equivalent to 40.025 gallons:

640.4 cups = 40.025 gallons

Alternative conversion

We can also convert by utilizing the inverse value of the conversion factor. In this case 1 gallon is equal to 0.024984384759525 × 640.4 cups.

Another way is saying that 640.4 cups is equal to 1 ÷ 0.024984384759525 gallons.

Approximate result

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

640.4 cup ≅ 40.025 gal

An alternative is also that one gallon is approximately zero point zero two five times six hundred forty point four 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