Pat,

You solve for R, the radius of the pizza, in the expression:

DW = 3.14159 x R^{2} x 0.085, where DW is the dough ball weight, and then double the value of R to get the diameter of the pizza.

In your example, the diameter equals 2 times the square root of 8/(3.14159 x 0.085) = 10.95 inches, or roughly 11 inches.

Peter