How much extra runner should you allow?

A bare length calculation is the number you need on the stairs, not the number you should order. Trimming, pattern matching and the odd mistake all consume material, and a short piece may require another cut or a revised fitting plan.

This calculator lets you apply 5%, 10%, 15% or a custom waste percentage, and shows the bare length and the order length side by side so you can see exactly what the allowance is costing you.

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.

How much waste to allow

Plain and textured runners with no repeat: 5% is usually enough. Striped or small-repeat patterns: 10%. Large geometric or floral repeats where every step must line up: 15% or more, and check the repeat length with the supplier.

Plain / sisal / boucle — 5%
Stripes and small repeats — 10%
Large repeats and borders — 15%+
Winders or awkward turns — ask the installer for a measured cutting allowance

Pattern repeat is not the same as percentage waste

If a pattern repeats every 24 in and you want the same point of the pattern on every tread, the effective length per step rounds up to a multiple of the repeat. A percentage covers ordinary trimming; a strict repeat needs the repeat length checked step by step.

Waste on the cost estimate

The cost estimator prices the rounded purchase length, not the bare length, so the waste allowance is reflected in the money figure as well as the material figure.

Questions people ask

What percentage of waste should I add to a stair runner order?: 10% suits most jobs. Drop to 5% for a plain runner with no pattern, and go to 15% or more for large repeats or a flight with winders.
Does waste include the offcut for repairs?: Not necessarily. If you specifically want a spare piece for a future repair, add its length on top rather than relying on the percentage.

Related guides

See all stair runner calculator guides