Runner length by number of steps

If you only know how many steps you have, this is the fastest route to a usable number. The reference figures below assume a 10 in tread and a 7.5 in riser — 17.5 in of runner per step — and no waste.

Change either dimension in the calculator to get the figure for your own staircase.

Your staircase

Optional starting measurements

Example measurements only, not building-code advice. Replace them with measurements from your own stairs.

Check a few steps before using one set of measurements for the whole flight.

Number of stairs

Count the tread-and-riser pairs the runner will cover. Exclude landings.

Tread depth (in)

Measure the runner path across the flat tread. Fractions like 10 1/2 work.

Riser height (in)

The vertical face between two treads.

Waste allowance

Custom%

10% is the starting allowance here, not a guarantee. Ask your fitter about patterns and turns.

Add a nosing / overhang allowance per step

Enter the extra runner path around the edge, including any underside wrap. Do not add it twice if it is already included in your measurements.

Your runner estimate

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

Length to order

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.

One step, shown in profile

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.

Runner length by number of stairs

8 steps: 140 in (11 ft 8 in). 10 steps: 175 in (14 ft 7 in). 12 steps: 210 in (17 ft 6 in). 13 steps: 227.5 in (18 ft 11.5 in). 14 steps: 245 in (20 ft 5 in). 15 steps: 262.5 in (21 ft 10.5 in). 16 steps: 280 in (23 ft 4 in). 18 steps: 315 in (26 ft 3 in). 20 steps: 350 in (29 ft 2 in).

Add your allowances

Every figure above is bare length. Add the measured landing travel first, then apply your chosen waste percentage to the combined base length before rounding up.

Count risers, not treads

Check both the covered treads and covered risers. The standard formula assumes one of each per entered step; a different start or finish needs a separate measured allowance.

Questions people ask

How much runner per step?: About 17.5 in on a standard US stair (10 in tread + 7.5 in riser) or about 41.5 cm on a typical UK stair.
Is the step count the same as the riser count?: Each entered step represents one covered tread plus one covered riser. Check the runner’s start and finish because the staircase’s tread and riser counts can differ.

Related guides

See all stair runner calculator guides