When you’re halfway through painting your home’s exterior, the last thing you want to do is find out you don’t have enough paint for the job. Not only are you faced with the hassle of another trip to the hardware store, but you may find yourself struggling to match your chosen color. To avoid potential delays and ensure you have enough paint, take the time to calculate how many gallons of paint your home needs before you pop open your first can.
Measure the height and width of each of the sides of your home using a tape measure. Use a ladder as needed to reach the second story. If you have a gable roof, find the height from the eaves of the roof to the peak, as well as the length of the eaves.
Multiply the width of each side of your home by its height to find the area. To find the area of a triangular part, such as the end of a gable roof, multiply 0.5 times the length of the eaves times the height from the eaves to the peak of the roof. Add the area of all four sides of your home together to find the total area.
Use your tape measure to find the height and width of each window, then multiply height and width to find the area of each of these components. Add the area of all doors and windows together and subtract it from the total area of your home you calculated in Step 3.
Choose your favorite paint and inspect the can to find its spread rate, which tells you how much surface area each gallon of paint will cover. The spread rate of many paints ranges from 250 to 350 square feet.
Divide the total area of your home by the spread rate of your chosen paint to determine how many gallons you need. Purchase this many gallons if you plan to apply a single coat of paint, or double this number if you plan to apply two coats.