How do I calculate square footage?

For a rectangle, multiply length by width in feet. For other shapes, use the matching shape mode or split the area into simple parts.

How many square feet are in a square yard?

One square yard is 9 square feet. Divide square feet by 9 to convert to square yards.

Square Footage Calculator

Calculate square footage for rooms, floors, walls, lots and simple shapes, with square yards, square meters, acres, waste and cost.

Area shape

Length, ft

Width, ft

Quantity

Waste / overage, %

Cost per sq ft, $

Square footage for rooms, surfaces and lots

Square footage calculators in the English SERP are practical measuring tools first. The primary answer is square footage, with optional waste, cost and metric conversions for shopping lists or estimates.

A r e a = L e n g t h \times W i d t h

For a rectangular room or surface, multiply the two dimensions measured in feet to get square feet.

For irregular rooms, split the surface into simple rectangles or use the L-shape mode, then add a waste allowance for cuts, layout and measurement error.

Frequently Asked Questions

Sources and References

Calculations are based on the listed reference sources. Links open in a new tab.

Updated: May 29, 2026

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