Room Area Calculator
Home & ConstructionCalculate floor, wall and ceiling area for a room, with doors and windows deducted.
Runs entirely in your browser — nothing is uploaded
Features
- Floor, ceiling, wall and volume in one go.
- Openings deducted to give a real paintable or tileable area.
- Answers in square feet, square metres and square yards.
- Works in feet, metres, inches or centimetres.
- Runs in your browser.
How to use the Room Area Calculator
- 1Enter the length, width and ceiling height.
- 2Set the number of doors and windows to deduct.
- 3Use the wall figure for paint and tiling, the floor figure for flooring.
Frequently asked questions
How do I calculate the area of a room in square feet?
Length in feet times width in feet. For an irregular room, split it into rectangles, work each one out and add them together — that is more reliable than trying to average the sides.
How is wall area different from floor area?
Wall area is the perimeter times the ceiling height, which is usually two to three times the floor area. It is the figure paint and wall tiling work from, which is why estimating paint from floor area goes so badly wrong.
What is the difference between carpet area and built-up area?
Carpet area is the usable floor inside the walls. Built-up area adds the walls themselves, and super built-up adds a share of common areas like lobbies and stairs. This calculator gives you carpet area — measure inside the room.