639 US customary cups in US gallons

Result

The conversion result is: 639 US customary cups is equivalent to 39.9375 US gallons.^[1]

Conversion formula
How to convert 639 US customary cups to US gallons?

We know (by definition) that: 1 uscup ≈ 0.0625 usgallon.

We can set up a proportion to solve for the number of US gallons.

1 uscup / 639 uscup ≈ 0.0625 usgallon / x usgallon

Now, we cross multiply to solve for our unknown x:

x usgallon ≈ (639 uscup / 1 uscup) * 0.0625 usgallon → x usgallon ≈ 39.9375 usgallon

Conclusion:

639 uscup ≈ 39.9375 usgallon

Conversion in the opposite direction

The inverse of the conversion factor is that 1 US gallon is equal to 0.0250391236306729 times 639 US customary cups.

It can also be expressed as: 639 US customary cups is equal to 1 / 0.0250391236306729 US gallons.

Approximation

An approximate numerical result would be: six hundred and thirty-nine US customary cups is about thirty-nine point nine three US gallons, or alternatively, a US gallon is about zero point zero three times six hundred and thirty-nine US customary cups.