A 12×12 ft wall is 144 square ft. To find the square footage of any wall, you need to multiply its width by its height.

100 square feet (ft²). A ten feet wide by ten feet tall wall has a square footage (or area) of 100 square feet. To get that result, you need to multiply its width by its height.

To calculate a room's wall square footage:

1. Pick a wall.
2. Find its width and height (in ft).
3. Multiply both dimensions together.
4. Repeat for every wall in the room and add the results together.
5. The outcome is the room's wall square footage.
6. Alternatively, you can add each wall's width and multiply the result by the room's height.