📐 Square Footage Calculator
Add up the square footage of rooms or areas, convert to square meters and acres, and estimate flooring with a waste allowance.
How the Square Footage Calculator Works
Square footage is the area of a floor or surface in square feet: length × width for a rectangle. For an L-shaped or irregular room, split it into rectangles, measure each one, and add them up — this calculator lets you enter several areas and totals them. You can measure in feet or meters; results are shown in both square feet and square meters, plus acres for larger areas.
When buying flooring, tile, carpet, or sod, installers usually add a waste allowance for cuts, pattern matching, and breakage — commonly about 5%–10% for simple layouts and more for diagonal or patterned installs. Enter a price per square foot to estimate the material cost.
Formula
Area (per rectangle) = length × width Total area = sum of all areas 1 square meter = 10.7639 square feet · 1 acre = 43,560 square feet Material needed = total area × (1 + waste %)
How to Use It
- Choose feet or meters.
- Enter the length and width of each room or section.
- Optionally add a waste percentage and a price per square foot.
- Read the total area and the material estimate.
Frequently Asked Questions
How do I calculate square footage?
Multiply length by width in feet. A room 12 ft by 15 ft is 180 square feet. For irregular rooms, divide them into rectangles and add the areas.
How many square feet are in a square meter?
One square meter is about 10.764 square feet, and one square foot is about 0.0929 square meters.
How much extra flooring should I buy?
A waste allowance of about 5%–10% is common for straightforward layouts; diagonal, herringbone, or patterned installs often need more. Check the manufacturer’s or installer’s recommendation.
How many square feet are in an acre?
One acre is 43,560 square feet, or about 4,047 square meters.
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Formula and content last reviewed: September 2026. All calculations run in your browser — nothing you enter is sent to or stored on our servers.
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See all →✔ Reviewed by GelirLab Editöryal Ekibi · Last reviewed: September 2026 · How we check our calculators