Total replacement cost combines material and labor, plus taxes and additional fees: Squares Needed = ceil(Roof Area × (1 + Waste%) ÷ 100) Material Cost = Squares × Material Price Per Square Labor Cost = Squares × Labor Price Per Square Subtotal = Material Cost + Labor Cost Additional Costs = Subtotal × Additional Costs % Subtotal With Additional = Subtotal + Additional Costs Tax Amount = Subtotal With Additional × Tax % Total Cost = Subtotal With Additional + Tax Amount Cost Per Sq Ft = Total Cost ÷ Roof Area Example: 1000 sq ft, $300 material, $50 labor, 10% waste, 8% tax - Squares = 11 - Material = $3,300; Labor = $550; Subtotal = $3,850 - Tax = $308; Total = $4,158 - Cost per sq ft = $4.16