We need the following implemented on a Magento site. We will be calculating square feet per box.
Lets say a customer needs 300 square feet at a price of $2 per square foot. Our boxes have 22.5 square feet. The customer would need 13.33 boxes (300/22.5 = 13.33). We only sell whole boxes. The customer would need to buy 14 boxes (14 x 22.5 = 315 square feet). The total cost to the customer would be $630.00 (315 x $2). We have this calculator working on our current oscommerce store.
A = Product Price
Y = amount of product needed
Z = amount of product in each box
E = number of boxes needed
D = total cost of boxes (square feet) needed
Y / Z = E x Z x A = D <----might be confusing sorry
All the customer would input is the amount needed (Y). It would probably be easier to price by the box, but we would still need to show the Square Foot Price. There are several example sites out there that I can show the winning bidder.