Tool

Free stair runner length calculator

Every part of this calculator is free and always will be: simple mode, advanced mode, cost estimating, seam planning, saved staircases and the printable quote.

There is no signup wall, no email capture and no upsell. The calculation runs in your browser, so your measurements never leave your device.

Your staircase

Start from typical stair sizes where you live

IRC-style stairs: 10 in minimum tread, 7¾ in maximum riser. Runners are usually 27 in or 32 in wide and sold by the linear foot.

Number of stairs

Count every step you will cover.

Tread depth (in)

Front edge to back of the step. Fractions like 10 1/2 work.

Riser height (in)

The vertical face between two treads.

Waste allowance

Custom%

10% is a common starting point; pattern matching and winders need more.

Add a nosing / overhang allowance per step

Needed when the runner wraps around a projecting nose (Hollywood installs and thick pads). Waterfall installs usually don't need it.

Your stair runner length

20 ft 3.1 in

Total runner required for 13 steps, including a 10% waste allowance.

Total runner length in each unit
Inches	243.1 in
Feet	20.26 ft
Feet & inches	20 ft 3.1 in
Yards	6.75 yd
Meters	6.17 m
Centimeters	617.47 cm

Recommended purchase length

21 ft

7 yd · 6.4 m · 252 in

This calculator provides an estimate based on the measurements and installation assumptions you enter. Complex, curved or winder staircases may require professional measurement.

Your measurements, drawn to scale

Side elevation of a staircase. The runner travels across each tread and down each riser, so every step consumes tread depth plus riser height of material.

What you get without paying anything

Runner length in inches, feet, yards and metres; waste and installation allowances; landing lengths; nosing allowance; a scale stair diagram; a materials list with rods, brackets, pads and tackless strip; and a full cost breakdown.

Unlimited calculations
Save staircases in your own browser
Print or download a spec sheet
Share a link that reopens your exact figures

Why it is free

The tool is a single static page with no server-side processing to pay for. Nothing you type is uploaded, stored or sold, so there is no data business behind it either.

Free does not mean rough

The calculation handles fractional treads, uneven bottom steps, landings, winder warnings and pattern repeat. It is the same arithmetic a fitter does on site, just without the mistakes.

Questions people ask

Is the stair runner calculator really free?: Yes — all features are free with no account, no email address and no usage limits.
Do you store my measurements?: No. Calculations run entirely in your browser. Saved projects are stored in your own browser storage and never sent anywhere.

Related guides

See all stair runner calculator guides