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Square footage calculator
Geometry
Result
Square feet
Square yards
Square meters
Region
Waste
Prices: national avg · Jun 2026 · sources
DiagramUpdates as you type

Calculate the square footage of a room or area, with instant conversions to square yards and square meters.

Formula

area = length × width

Method & sources
Formula basisEuclidean geometry
How we calculateArea by shape (rectangle L×W, circle πr², triangle ½bh), summed across regions.
Formula verified against the published standard above. Method last reviewed June 2026. Estimates are for planning — confirm against supplier quotes.

How it works

Square footage is simply length times width in feet. For odd shapes, split into rectangles and add them up.

Conversions

One square yard is 9 square feet; one square meter is about 10.76 square feet.

Worked example

An L-shaped room

For a simple rectangle, square footage is just length times width — a 12 x 10 ft room is 120 square feet. For an L-shaped or irregular room, split it into rectangles, calculate each, and add them up.

Say an L-shaped room is a 12 x 10 ft section plus a 6 x 8 ft section: that's 120 + 48 = 168 square feet. This split-and-add method handles almost any floor plan. For triangles, use half the base times the height; for circles, π times the radius squared.

What affects your result

Common mistakes to avoid

Where the numbers come from

Pure geometry — no estimation. Use this to feed area into the flooring, tile, paint, and other calculators.

Frequently asked questions

How do I calculate square footage?

Multiply length by width in feet. A 12×10 room is 120 square feet.

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