Square footage
calculator
Rooms, decks, lawns, countertops, measure the sides, pick the shape, and get the area. Add a price per square foot and the material budget appears with it.
Measuring up a job?
A few solid picks. As an Amazon Associate, Calculate.to earns from qualifying purchases, at no extra cost to you.
ROATEE Construction Calc
Feet-inch-fraction engineering calculator for carpenters, framers and contractors on site.
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OSALO Desktop Calculator
Extra-large 12-digit LCD, giant buttons, solar + battery, the classic office desk workhorse.
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Casio fx-83GTCW+
The UK classroom-standard scientific calculator (also in pink), allowed in most UK exams.
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Helix Oxford Scientific
240-function scientific calculator for KS3–KS4 maths, with hard cover. Exam-friendly, plastic-free packaging.
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The three shapes that cover most jobs
Rectangles are length × width; circles are π times the radius squared (measure the diameter and halve it); triangles are base × height ÷ 2. Awkward rooms decompose: an L-shape is two rectangles, measure each, add them.
Pricing per square foot
Materials and trades quote per square foot, flooring, tile, paint coverage, lawn care, even rent. Multiply area by rate and the budget is instant. For materials, remember the waste factor: cuts and breakage add 5–15%, the flooring calculator builds that in, and paint converts wall area into cans.
Square footage FAQ
Multiply length by width in feet, a 16 × 12 room is 192 sq ft. For L-shaped rooms, split into rectangles and add the pieces.
Measure the diameter, halve it for the radius, then πr². A 10-foot round patio is π × 25 ≈ 78.5 sq ft.
Divide by 10.764, 192 sq ft is about 17.8 m².
Yes, cutting waste and breakage typically add 5–10% for flooring and 10–15% for tile laid diagonally. Order above the raw area.