660 dry quarts in US quarts
Result
The conversion result is: 660 dry quarts is equivalent to 768.007142857143 US quarts.[1]
Conversion formula
How to convert 660 dry quarts to US quarts?
We know (by definition) that: 1 dryquart ≈ 1.16364718614719 usquart.
We can set up a proportion to solve for the number of US quarts.
1 dryquart / 660 dryquart ≈ 1.16364718614719 usquart / x usquart
Now, we cross multiply to solve for our unknown x:
x usquart ≈ (660 dryquart / 1 dryquart) * 1.16364718614719 usquart → x usquart ≈ 768.0071428571454 usquart
Conclusion:
660 dryquart ≈ 768.0071428571454 usquart

Conversion in the opposite direction
The inverse of the conversion factor is that 1 US quart is equal to 0.00130207122329591 times 660 dry quarts.
It can also be expressed as: 660 dry quarts is equal to 1 / 0.00130207122329591 US quarts.
Approximation
An approximate numerical result would be: six hundred and sixty dry quarts is about seven hundred and sixty-eight point zero zero US quarts, or alternatively, a US quart is about zero times six hundred and sixty dry quarts.
Footnotes
[1] The precision is 15 significant digits (fourteen digits to the right of the decimal point).
Results may contain small errors due to the use of floating point arithmetic.