Calculate the square footage of the area you want to paint. Divide the square footage by 350 (the average square footage a gallon of paint covers). Multiply the number of gallons you need by two, as you’ll likely be applying two coats of paint. For a more accurate estimate, subtract the square footage of the windows and doors from the initial square footage total. It’s a good idea to plan for an extra gallon of paint to make sure you have enough to finish the job.

To calculate the square footage of a home exterior, painters multiply the length of the wall by the height of the wall to be painted. Then they add the total square footage for all of the walls to be painted. To calculate the price, they multiply the total square footage by their cost per square foot to prep and paint. Additional costs may factor in such as repairs, additional trim, and walls higher than the first story.

The cost to paint the exterior of a house ranges from $1,900 to $4,500 or about $1.50 to $4 per square foot, depending on the size, height, and complexity of the home layout. Other cost factors include your location, the type of siding (e.g., wood, aluminum, brick, stucco, etc.), and the kind of paint (e.g. oil-based, latex, acrylic, etc.). Painting the trim a different color or painting intricately designed trim can also increase the cost.

You should apply at least two coats of paint when painting the exterior of your house. Two coats of paint provides better durability and more even coverage than just one coat.