Exterior Paint

Use this tool to estimate how many gallons of paint you'll need for an exterior project.


Round up to the nearest foot, and be sure to count all lengths. A rectangular garage that's 8 x 15, for example, is 8 + 15 + 8 + 15 = 46 feet total in length. The total length of a house with ells, extensions, and bays needs to be calculated wall by wall.

If you don't know how tall the wall is, assume about 10 feet for each story, or 20 feet for a two-story house and 30 feet for a three-story house. If you have a pitched roof that creates a higher wall on one side of the house than the other, use the average height. For each overhang, add two feet to the wall height.

Windows and Doors

This section will estimate the amount of paint you need to cover the doors and the door and window trim, and will subtract the area of those openings from the wall measurements. For house exteriors, many professional painters figure windows and doors "solid"  that is they don't subtract the window and door area from the wall area total, because it represents such a small percentage of the overall paint coverage. To figure your project "solid", leave this section blank when calculating the walls, then calculate again filling in this section and leaving the wall section blank.

Window Trim

Round up to the nearest inch on these measurements.

Door and Door Trim

Round up to the nearest inch on these measurements.