Room Area and Square Footage Calculator
Works out the areas of a rectangular room.
Floor area
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Share sends a link that reopens these numbers. Copy details pastes the full breakdown as a list.
In square feet — ft²
In square metres — m²
Ceiling area —
Wall area, less doors and windows —
Perimeter —
The formula
floor = length × width walls = 2 × (length + width) × height − openings
Openings are taken at about 1.8 m² per door and 1.5 m² per window.
What to watch out for
For an L-shaped room, split it into rectangles and add them up.
Frequently Asked Questions
How do I work out square footage?
Multiply the length by the width in feet. A 5 × 4 m room is 20 m², or 215.3 ft².
How many square feet are in a square metre?
10.764.