Square Footage Calculator

This calculator lets you pick a shape for each room, computes each room's area, then adds them all together into one grand total. Example: a rectangular living room 4m × 3m = 12 m², a circular nook with a 2m diameter = π × 1² ≈ 3.14 m², and a triangular attic corner with a 2m base and 1.5m height ÷ 2 = 1.5 m². Adding all three gives a total of 12 + 3.14 + 1.5 = about 16.64 m² (roughly 179.2 ft²). Click 'Add Room' to add more rows, and the input fields (width/length, diameter, base/height, etc.) automatically change to match the shape you pick for that row.

Measure at floor level — measure where the floor meets the wall, not along the ceiling, so your numbers reflect usable floor space. Add closets and alcoves as their own rows instead of eyeballing them into a bigger room — small nooks add up and rough guesses create real errors. Watch out for wall thickness: this tool assumes the interior (usable) dimensions you enter, which can differ from the gross floor area shown on architectural plans that include wall thickness. For an official area figure, check your property deed or building registry.

A combined multi-room total is handy for flooring or carpet estimates (price per m²/ft² × total area), paint and renovation budgeting, and listing square footage when advertising a property. If you only have one room and need the exact formula and perimeter (for example to calculate wallpaper or molding length), use the single-shape Area Calculator instead.