When it comes to estimating the cost of roofing materials, it's important to start by calculating the total square footage of the roof. This can be done by measuring the length and width of each plane on the roof, including any dormers, and multiplying the length by the width to get the square footage of each plane. Once you have the total square footage, divide it by 100 to determine the number of squares on the roof. Since three packs of shingles are needed to cover a square, plan to buy three packs for each square.
To account for any waste, add 10% to the number of packs you need. By following these steps, you can accurately estimate how many shingles you'll need for your roofing project. It's important to remember that this is just an estimate and that actual costs may vary depending on the type of shingles you choose and other factors.