Carpet Stairs Calculator
Enter step count, stair width, rise, and tread depth to get the total linear feet and square footage of carpet for a staircase.
Stairs
You'll need
Stairs narrower than a 12-ft roll cut from one strip. Add pad and tack strip separately. Always run pile in the same direction down the stairs.
How to estimate carpet for stairs
Each step needs rise + tread + wrap allowance in inches. Multiply by steps for total inches, divide by 12 for linear feet, and add 15% waste. Multiply by stair width for square footage. Always run pile direction down the stairs and buy pad separately.
Measure stair dimensions from a LiDAR scan
ProBuildCalc turns your iPhone's LiDAR scanner into a job-site measuring kit — walk the space and it captures the square footage, material takeoff, and a blueprint automatically. No tape measure, no graph paper.
Carpet stairs FAQ
- How much carpet do I need for stairs?
- For each step, add the tread depth and rise height in inches, plus 2 inches for the waterfall fold or 4 inches for an upholstered wrap. Multiply by the number of steps and divide by 12 for linear feet. Add 15% waste.
- What is the difference between waterfall and upholstered carpet stairs?
- Waterfall carpet folds straight down from the nosing to the riser — easier to install and common in residential work. Upholstered (or cap-and-band) carpet wraps under the nosing and tacks to the riser — a cleaner look but requires more material and labor.
- How much waste should I add for carpet on stairs?
- Add at least 15% for a plain carpet and 20% or more for patterned carpet where the design must match between steps. Stairs produce more offcuts than flat rooms.
- Do I need pad under stair carpet?
- Yes — stair pad (usually thin, dense rubber or foam) is tacked to each tread and riser before the carpet goes on. It protects the carpet backing and adds cushion. Measure and buy pad to match your stair count and width.
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See also: estimating guides · ProBuildCalc by trade