Square Footage Calculator
Calculate square footage of any room or area.
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How It Works
Calculates the square footage of a rectangular space by multiplying length by width. Used for flooring, paint, real estate, and landscaping projects.
Formula
Area = Length x WidthQuick Reference
Common calculations — results you can verify instantly.
12×15 room
12×15
180 sq ft
10×12 bedroom
10×12
120 sq ft
20×40ft lot
20×40
800 sq ft
Tips & Shortcuts
For L-shaped rooms: split into two rectangles, calculate each, then add.
Real estate square footage typically does not include garages, unfinished basements, or exterior walls.
For tile: add 10% for cuts and waste.
Common Mistakes
Measuring in mixed units (some in inches, some in feet)
Convert all measurements to feet before multiplying. 6 inches = 0.5 feet.
Forgetting irregular spaces (closets, alcoves)
Measure each rectangle separately and sum them. Irregular shapes need to be broken into rectangles.
Frequently Asked Questions
12 × 15 = 180 square feet.
Measure the room in feet, multiply length × width. Add 10% for waste and cuts. Buy that amount.
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