How much carpet for 13 stairs?
Estimate each tread+riser as roughly 2 sq ft per step (varies by overhang). 13 stairs ≈ 26 sq ft per foot of width — a 3 ft wide run needs ~78 sq ft plus 15% waste ≈ 10 sq yd.
Stair Carpet Calculator
Stair carpet is ordered in square yards like room carpet — but cuts, bullnose, and winders eat extra material. Default 15% waste is higher than flat rooms; measure each flight carefully.
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Default 10%
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Use the installed or material quote converted to square feet
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Measuring stairs
Estimate each tread plus riser as roughly 2 sq ft per step per foot of stair width — a 13-step, 3 ft wide run is often 75–80 sq ft before waste.
For box stairs, measure one box step as a mini rectangle. Winders and pie-shaped steps need individual measurements entered as separate “rooms.”
Pad and installation
Order pad in the same square yards as carpet — use thin, dense stair pad rated by your carpet manufacturer. See our carpet pad guide.
Choosing carpet type? Read how to choose carpet for rooms for fiber and pile by traffic level.
Related guides
Frequently asked questions
How much extra waste for stairs?
Use 15–20% waste for stairs vs 10% for flat rooms. Bullnose, winders, and pattern matching consume more material.
Do I need pad on stairs?
Yes — use thin, dense stair pad or the pad recommended by your carpet manufacturer. Order pad in the same square yards as carpet.
Related calculators
Flooring Box Calculator · https://flooringboxcalculator.com/stair-carpet-calculator/