In order to estimate roofing, you can follow this procedure: measure the height of the widest point in your home. The width of this point is what may be closest to your size requirement; it will help you figure out how much material is needed. talk to a professional who can assess your needs and help you choose which materials are best for your situation based on their durability and quality. find out the cost for the materials you want to use. Local stores and manufacturers may have different prices, so compare them before deciding on a final choice. work with the roofing contractor to get an estimate for the size, shape, and placement of the new roof that you’ll need. get estimates from different contractors and compare their prices so that you can choose which one is best for your needs. get estimates from local companies in your locality to comparison shop and put together a budget proposal with them.