639 imperial cups in US customary cups

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

We know (by definition) that: $1\mathrm{brcup}\approx 1.20094992550486\mathrm{uscup}$

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

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

Conclusion: 639 ⁢ brcup ≈ 767.4070023976054 ⁢ uscup

Conversion in the opposite direction

The inverse of the conversion factor is that 1 US customary cup is equal to 0.00130308949081219 times 639 imperial cups.

It can also be expressed as: 639 imperial cups is equal to $\frac{1}{\mathrm{0.00130308949081219}}$ US customary cups.

Approximation

An approximate numerical result would be: six hundred and thirty-nine imperial cups is about seven hundred and sixty-seven point four zero US customary cups, or alternatively, a US customary cup is about zero times six hundred and thirty-nine imperial cups.