Stair Carpet Calculator

Calculate carpet needed for stairs — either a runner or full-wrap installation. Includes padding and tack strips.

Results

Visualization

How It Works

Stair carpet is measured as a continuous strip. Each step needs carpet for the tread (horizontal) plus the riser (vertical), plus extra for tucking.

The Formula

Length = Steps x (Tread + Riser + Tuck) + 12" landing

Variables

  • Tread — Horizontal surface of each step (10-11")
  • Riser — Vertical face between steps (7-8")
  • Tuck — 1" for waterfall, 2" for Hollywood wrap

Example

13 steps waterfall: 13 x (10 + 7.5 + 1) + 12 = 252.5" = 21 ft of carpet.

Tips

  • Waterfall installation is easier for DIY — the carpet drapes over the nose.
  • Hollywood wrap looks more custom but requires more skill and carpet.
  • Use a 27" runner for a classic look, leaving 4-5" of stair exposed on each side.
  • Stair carpet wears faster than floor carpet — choose a dense, low-pile style.

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