Stair Runner Length CalculatorAllowance
Stair runner length calculator with waste allowance
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 runner that is two inches short is scrap.
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.
Stair runner calculator
Your stair runner length
20 ft 3.1 in
Total runner required for 13 steps, including a 10% waste allowance.
| 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
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 an awkward flight — add 5% on top
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?
- Usually yes at 10%. If you specifically want a spare piece for a future repair, add its length on top rather than relying on the percentage.