639 US customary cups in US quarts

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

We know (by definition) that: $1\mathrm{uscup}\approx 0.25\mathrm{usquart}$

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

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

Conclusion: 639 ⁢ uscup ≈ 159.75 ⁢ usquart

Conversion in the opposite direction

The inverse of the conversion factor is that 1 US quart is equal to 0.00625978090766823 times 639 US customary cups.

It can also be expressed as: 639 US customary cups is equal to $\frac{1}{\mathrm{0.00625978090766823}}$ US quarts.

Approximation

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