Stair Runner Length CalculatorStair type
Stair runner length calculator for spiral stairs
A spiral stair cannot take a continuous runner — every tread is a wedge, and the runner would twist. What people actually fit is a set of individually cut and bound tread pads.
To estimate material, work out the depth of one tread on the runner's centre line, multiply by the number of treads, then add generous waste for the wedge shape.
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
Estimating spiral tread pads
Measure the tread depth at the point where the middle of the pad will sit. Twelve treads at 12 in on the centre line is 144 in of length, but because each piece is cut from a rectangle you should budget 30 to 40% waste.
Risers are usually left bare
On spirals the risers are often open or metal, so no riser allowance is needed. Set the riser height to zero in the calculator if you are only covering treads.
Binding and fixing
Every pad needs its edges bound, and fixing is usually double-sided tape or adhesive rather than rods. Factor binding per piece into the cost estimate as an accessory line.
Questions people ask
- Can you put a runner on a spiral staircase?
- Not as one continuous piece. Spiral stairs take individually cut, bound tread pads shaped to each wedge.
- How much material do spiral tread pads use?
- Roughly the tread depth at the pad centre × number of treads, plus 30 to 40% waste because each wedge is cut from a rectangle.