Square Footage Calculator

Add up rooms and shapes — rectangles, circles, triangles — for total square footage, with optional cost per sq ft.

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Measuring Like a Contractor

Break the space into simple shapes, compute each, and sum: rectangle = L × W, circle = π × (d/2)², triangle = base × height ÷ 2. An L-shaped room is just two rectangles. Add rows per area; the tool totals square footage and — with a price per sq ft — the project cost. Results also show m² for metric materials.

Trade conventions: flooring is ordered with 5-10% cutting waste on top; painting uses wall area (perimeter × height minus openings — our Paint Calculator handles that); real-estate square footage counts finished, heated space measured from exterior walls. Measure twice at the baseboard, not the ceiling.

Frequently Asked Questions

How much flooring waste should I add?

5% for straight-lay planks in simple rooms, 10% for diagonal patterns, tile, or rooms with many jogs. Buy it all from one dye lot.

How do I measure an odd-shaped room?

Sketch it, slice it into rectangles and triangles at natural break lines, measure each, and enter one row per piece. Small bump-outs can be measured as their own rectangles.

Is square footage the same as usable space?

No — listings often include interior walls and exclude balconies differently by market. For furniture and flooring, trust your own tape, not the listing.

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