Stair Carpet Calculator

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Construction

Calculate how much carpet you need to cover a staircase.

Formula

LF = steps × (tread + riser + tuck) / 12; Sq yd = LF × width / 12 / 9
  • Add 3–6 in per step for tucking and nosing.
  • Standard carpet is sold in 12 ft wide rolls; divide square footage by 12 to get roll length.
  • Add 10% for waste and pattern matching.

13 steps, 10 in tread, 7.5 in riser, 36 in wide, 3 in tuck

Inputs
  • Number of Steps: 13 steps
  • Tread Depth: 10 in
  • Riser Height: 7.5 in
  • Stair Width: 36 in
  • Extra per Step (tuck/overlap): 3 in

Per step: 10+7.5+3 = 20.5 in. Total: 13×20.5 = 266.5 in = 22.21 ft. Width: 36 in. Sq yd = 22.21×3/9 = 7.40 sq yd.

Frequently asked questions

How is carpet measured for stairs?
Measure the combined tread depth and riser height for each step, plus 3–4 inches for tucking. Multiply by the number of steps and the stair width.