Stair Carpet Calculator

Measure the full tread-and-riser path so a stair runner estimate includes nosing wraps and landings.

Stair carpet lengthThe runner path is rounded through physical roll-width lanes.

9.25linear yards for straight stair strips

Runner length per lane: 24.125 ft
Roll-width lanes: 1
Order length: 27.744 ft
Order length: 9.25 linear yd

Measure around the actual tread, nosing, and riser profile. Pattern alignment, waterfall versus cap-and-band installation, turns, landings, and binding can add material.

Show calculation

[13 × (10 + 7.5 + 2) in ÷ 12 + 3 ft] × 1 × 1.15 = 27.74 ft

Transparent method and editable product assumptions. Verify current labels and project requirements.

How this calculator works

Each covered step adds the measured tread depth, riser height and an explicit nosing-wrap allowance. Landing path is added as a separate straight length.

If the covered stair width exceeds usable roll width, the estimate adds whole parallel lanes before applying the selected cutting or pattern allowance.

Cap-and-band and waterfall methods may measure differently. Turns, pie steps, patterned goods, binding, seam locations and landing orientation require a detailed installer plan.

Formula

Length = [steps × (tread + riser + nosing wrap) + landing] × roll-width lanes × allowanceThe live result shows runner length and linear yards.

Control example: 13 straight steps

Each step uses 10 + 7.5 + 2 = 19.5 in of runner path; add a 3 ft landing.

One lane needs 24.125 ft. With 15% allowance, order about 9.25 linear yards.

Assumptions and limits

Measure around the actual tread, nosing and riser profile and confirm usable roll width, pattern repeat and installation method.
Measurements describe one simple project geometry.
Waste and package values are editable planning assumptions.
It does not check stair code, choose an installation method, lay out turns or winders, optimize seams, or quote labor.

Common measuring mistakes

Mixing nominal dimensions with actual installed coverage.
Skipping whole-package or stock-length rounding.
Failing to verify the page’s stated measurement and product assumptions.
Using a planning estimate outside the limitations stated on this page.

Sources

Product-specific values remain editable. These sources support the method and stated examples; they are not a universal substitute for your supplier’s current label.

CRI carpet installation resources Treats carpet layout, seaming and installation method as product- and project-specific.
GQ Calc methodology Documents length-path geometry, unit conversion and allowance rounding.

Questions people ask

What does the Stair Carpet Calculator calculate?

Calculate stair carpet runner length and linear yards from tread depth, riser height, nosing wrap, step count, stair width, landing, and roll width.

How does this stair carpet calculator work?

Length = [steps × (tread + riser + nosing wrap) + landing] × roll-width lanes × allowance

Which measurements should I enter?

Measure around the actual tread, nosing and riser profile and confirm usable roll width, pattern repeat and installation method.

Does the estimate include every project requirement?

No. It does not check stair code, choose an installation method, lay out turns or winders, optimize seams, or quote labor.

Can I use metric measurements?

Yes. Switch to Metric above the form. The calculator converts the displayed measurements while keeping the same geometry and whole-item rounding.