If one needs to figure out waste here would be one way:
Weigh out the fabric ..
Divide the total weight of the yardage into the waste weight that equals the % of waste.(it will come out in a fraction example : .40) now multiply that fraction times the cost of yardage and the product is the amount of $ wasted..
Example : 1yd @ $10.00 weighing out at 16 oz. total
say your waste weighs out at 3.2 ozs. total
Divide the 16 ozs (yardage) into the 3.2 ozs (waste) that would equal .20 (or 20%). Now take the .20 (waste percentage) multiply times the $10.00(yardage cost) this will equal $2.00 (cost of waste).