Step count

Stair runner length calculator for 15 steps

Fifteen risers usually means a taller ground floor — Victorian, Edwardian or a newer home with 9 ft ceilings.

With a 10 in tread and a 7.5 in riser, 15 steps need 262.5 in: 21 ft 10.5 in, or 6.67 m.

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.

The 15 step numbers

Bare 262.5 in. Plus 10% waste: 288.8 in (24 ft 1 in). Add a 1 in nosing allowance per step and it rises to 277.5 in bare, 305.3 in ordered.

Nosing matters more on long flights

A one inch nosing wrap costs 15 in across a 15 step flight — more than a whole extra step. If your treads have a pronounced bullnose and you are fitting waterfall style, include the allowance.

Deeper treads change everything

Swap the 10 in tread for an 11 in tread and the same 15 steps need 277.5 in bare. Always measure rather than assuming.

Questions people ask

How much stair runner for 15 steps?: About 21 ft 10 in (6.7 m) before waste, or roughly 24 ft (7.3 m) with a 10% allowance.
Should I add nosing allowance?: Add about 1 in per step if the treads have a pronounced nosing and the runner will wrap over it.

Related guides

See all stair runner calculator guides