Room Area Calculator
Quickly calculate a room's floor area and perimeter in imperial or metric units.
How this calculator works
Area is length × width. Perimeter is 2 × (length + width). Both figures are shown in square feet and square meters regardless of which unit you enter.
Enter length and width in feet or meters — the calculator converts and displays area in both sq ft and sqm automatically, so you never need to convert by hand.
All calculations run in your browser only — nothing you type is sent to a server. Results are estimates for planning purposes; always round up and buy a small surplus for cuts, waste, and future repairs.
Example calculations
12 × 10 ft room
120 sq ft (11.15 sqm), perimeter 44 ft.
4 × 3.5 m room
14 sqm (150.7 sq ft), perimeter 15 m.
Frequently asked questions
Does this include alcoves or irregular room shapes?
This calculator assumes a simple rectangle. For an L-shaped or irregular room, split it into rectangular sections, calculate each separately, and add the areas together.
What's the difference between area and perimeter?
Area (length × width) tells you how much floor surface you're covering — useful for flooring, tile, or carpet. Perimeter (the distance around the edge) is useful for baseboards, trim, or wallpaper border.