📐 Square Footage Calculator
Square footage = length × width. Enter the dimensions to get the area in both square feet and square metres, with a multiplier for repeated areas. Enter your values below — results update instantly, entirely on your device.
12 × 10 ft
× 0.092903
How the square footage calculator works
Area = length × width. For a rectangular room, multiply the two sides in the same unit. To cover several identical rooms or sections, multiply that area by the count. 1 ft² = 0.092903 m²; 1 m² = 10.7639 ft².
Example: A 12 ft × 10 ft room is 120 ft², which is 120 × 0.092903 ≈ 11.15 m². Four such rooms total 480 ft².
For L-shaped or irregular spaces, split them into rectangles, work out each area separately and add them up. For flooring, paint or tile, add a waste allowance (usually 5–10%) on top of the bare square footage before you buy.
Frequently asked questions
How do I calculate square footage?
Measure the length and width in feet and multiply them: a 12 ft by 10 ft room is 12 × 10 = 120 square feet. Keep both measurements in the same unit before multiplying.
How do I find the square footage of an irregular room?
Divide the space into rectangles, calculate each rectangle's area (length × width) separately, and add them together. This handles L-shaped rooms and alcoves.
How many square feet are in a square metre?
One square metre equals about 10.764 square feet, and one square foot equals 0.092903 square metres. This calculator shows both units at once.
How do I convert room dimensions in inches?
Divide inches by 12 to get feet first (e.g. 144 in = 12 ft), then multiply length by width. Or measure in metres and switch the unit selector.
Should I add extra for flooring or paint?
Yes — add a waste allowance, typically 5–10% for flooring and tile to cover cuts and mistakes. Calculate the bare square footage here, then multiply by 1.05–1.10.
Is this square footage calculator accurate and private?
Yes. It uses the standard published formula, shows its working under every result, and computes locally in your browser — your inputs are never sent to a server, and the page works offline.