Square Footage Calculator
Flooring, paint, tile or a real-estate listing: measure each area, add them up, and get the total in both sq ft and m² — with material cost and the waste buffer pros use.
Spotted a mistake or have an idea? — errors get fixed and credited publicly.
Last reviewed: July 20, 2026 · Formulas verified by automated tests before every release.
Measuring like a pro
- Measure twice at floor level — walls lean, floors don't lie. For flooring, the floor measurement is the one that matters.
- Odd shapes are just rectangles in disguise: L-shape = 2 rows, U-shape = 3 rows in this calculator.
- Closets and alcoves count for flooring but often not for paint — know which project you're measuring for.
- The 10% waste buffer is not pessimism — it's cuts, breakage and pattern matching. Running out mid-floor costs more than the extra box.
Area = Length × Width · sq ft ÷ 10.764 = m² · Material = Area × price (+10% waste)
Frequently asked questions
How do I calculate square footage?
Length × width, measured in feet. A 12 × 10 room is 120 sq ft. For several rooms, calculate each and add them up — the calculator does this with separate rows.
How do I measure an L-shaped or irregular room?
Split it into rectangles: an L-shape is two rectangles, a U-shape is three. Add each as a separate row and the calculator sums them. For angled walls, measure the widest points — slight over-ordering beats a mid-project store run.
How do I convert square feet to square meters?
Divide by 10.764: a 500 sq ft studio is about 46.5 m². The calculator always shows both units.
Why add 10% for waste?
Flooring, tile and paint jobs lose material to cuts, breakage and pattern matching. 10% is the standard buffer for straight layouts; diagonal or patterned installs may need 15%.