let`s see, that`s # of square inch wing area divided by 144. Then divide the weight in ounces by the area in square feet. right?

wing 50 inch span x 10 inch chord = 500 sq. in.
weight is 5 lbs x 16 ounces = 80 ounces.

500sq.in divided by 144 = 3.472
80 ounces divided by 3.472 = 21.38 oz/sq.ft.

Midwest Sweet Stick ....