Area of Four Walls
The four walls of a room consist of two pairs of opposite walls. The area is calculated by multiplying the perimeter of the floor by the height of the room.
Formula
Area of 4 walls = 2h(l + b)
Where l = length, b = breadth, and h = height.
Area of Floor and Ceiling
In a standard rectangular room, the floor and the ceiling have the exact same dimensions and area.
Area of Floor = length × breadth = l × b
Area of Ceiling = length × breadth = l × b
Total (Floor + Ceiling) = 2(l × b)
Total Surface Area
The total surface area includes the four walls, the floor, and the ceiling (6 surfaces in total).
Total
TSA = Area of 4 walls + Area of Floor + Area of Ceiling
TSA = 2h(l + b) + 2lb = 2(lh + bh + lb)
Area Excluding Openings
When painting or wallpapering, we must subtract the area of windows and doors from the total wall area.
Net Wall Area = [Total Area of 4 Walls] - [Area of Windows + Area of Doors]