How to Calculate Materials in Construction

As a construction contractor, material costs are an important price point when estimating total cost with labor. Many contractors must purchase materials before getting paid by a customer, so you also need to know how much cash you have to advance for each build. Before calculating the material cost, create a list of all the materials necessary to complete the project. The list becomes a reference when you visit the store. You can compare prices of different materials based on your list and create the most cost-effective estimate for you and your customer.

Step 1

Write down the measurements of all your construction materials. Organize your list by type of construction material if you need more than one type, such as carpet, siding or sheet rock. Next to the name of the material, write the measurement for length and width or length and height. For example, if you need to buy siding, write down the length and height of the siding in feet.

Step 2

Calculate any square footage for your materials by multiplying the length and width or height and length. For example, if your siding measures 20 feet in length with a height of 8 feet, you need 160 square feet of siding.

Step 3

Calculate any subtractions from your square footage, such as a garage door. In the example, if one siding is 160 square feet, but you have a garage door that is 16 feet in length and 7 feet in height, you subtract the square footage of the garage door from the square footage of the total siding. The square footage of the garage door is 112. Subtract 112 from 160, and you get 48 square feet.

Step 4

Add the total amount of materials in square footage. For total siding, add up the square footage for each wall and garage door siding. In total, you need siding for three walls measuring 160 square feet and one wall of siding for 48 square feet. Once added, you need 528 square feet of siding.

About the Author

C.K. Adams has worked in the newspaper and publishing field since 2003. Specializing in literature, education, crafts and science, she contributes to the University of Florida's fiction collective and "Tea Magazine." Adams earned her Bachelor of Arts in English from the University of Florida.