Wall Paint Area Calculator

This wall paint area calculator estimates the paintable surface area for common wall types such as single walls, walls with openings, accent walls, sloped walls, and L-shaped rooms. Formulas are provided below.

Single Wall
The paintable area of a flat wall is A = length × height, where length is the horizontal run and height is from floor to ceiling. For a wall 15 ft wide and 9 ft high, the calculator gives A = 15 × 9 = 135 ft².

Wall with Openings
To adjust for windows or doors, subtract their area from the total: A = (wall length × wall height) – (window area + door area). For a 12 × 9 ft wall with a 3 × 4 ft window and 3 × 7 ft door, A = 108 – (12 + 21) = 75 ft² using the calculator.

Accent Wall
An accent wall’s area is calculated the same as a regular wall: A = width × height. This is useful for estimating unique finishes or textures. For a 10 ft wide wall with 8 ft height, the calculator gives A = 10 × 8 = 80 ft².

Sloped Wall
The area of a sloped wall is A = ½ × base × height, treating it like a triangle. For a wall 14 ft long and 6 ft tall at its peak, the paint calculator returns A = ½ × 14 × 6 = 42 ft².

L-Shaped Room
For L-shaped rooms, divide the wall layout into sections and sum the areas using A = A₁ + A₂ + A₃… as needed. For three walls: 10 × 9, 8 × 9, and 12 × 9 ft, total paintable area is A = 90 + 72 + 108 = 270 ft².

Paint ordering advice: Start by calculating each wall face individually. A 12 × 9 ft wall yields 108 square feet, but don’t forget to subtract for windows. For round cutouts or archways, reference the area calculator — it handles circles, ellipses, and other shapes most paint tools miss.