How can I calculate square feet of a wall?

To calculate the square footage of a wall, you need to know the height and length of the wall, as well as any additional features of your room like windows or doors, that may affect the measurements. Step 1: Measure the height of the wall from the floor to the ceiling. Step 2: Measure the length of the wall from one end to the other. Step 3: Multiply the height by the length to get the square footage of the wall. Example: If the height of the wall is 8 feet and the length is 10 feet, the square footage of the wall is 80 square feet (8 x 10).