Typical length by step count
| Number of steps | Raw length (10 in tread / 7.5 in riser) | With 10% waste allowance |
|---|---|---|
| 10 | 175 in / 4.44 m | 192.5 in / 4.89 m |
| 12 | 210 in / 5.33 m | 231 in / 5.87 m |
| 13 | 227.5 in / 5.78 m | 250.3 in / 6.36 m |
| 14 | 245 in / 6.22 m | 269.5 in / 6.85 m |
| 16 | 280 in / 7.11 m | 308 in / 7.82 m |
| 18 | 315 in / 8 m | 346.5 in / 8.8 m |
The math behind the numbers
Each step adds one tread depth plus one riser height to the total length, since the runner follows the tread surface then wraps down the riser face before starting the next tread. A standard tread depth of 10 in (25 cm) plus a standard riser height of 7.5 in (19 cm) gives 17.5 in (44 cm) per step, which is then multiplied by the number of steps and topped up with a waste allowance.
Know your numbers in 30 seconds
Enter your step count, tread depth and riser height — the stair runner calculator gives you the exact length to order, in metres and feet, with waste included.
Open the stair runner calculatorWhy standard dimensions vary
| Stair type | Typical tread depth | Typical riser height |
|---|---|---|
| Standard US residential | 10-11 in (25-28 cm) | 7-7.75 in (18-20 cm) |
| Standard UK residential | 9.5-10.5 in (24-27 cm) | 7-7.9 in (18-20 cm) |
| Steep or older builds | 8-9 in (20-23 cm) | 8-8.25 in (20-21 cm) |
| Shallow, wide staircases | 11-12 in (28-30 cm) | 6.5-7 in (16.5-18 cm) |
Feet and metres at a glance
- A 12-step flight typically needs about 17.5-19 ft (5.3-5.9 m) including waste.
- A 13-step flight typically needs about 19-21 ft (5.8-6.4 m) including waste.
- A 16-step flight typically needs about 23-26 ft (7-7.8 m) including waste.
- Add 3-5 ft (0.9-1.5 m) more for a flight with a landing or 90-degree turn.
Why a rule of thumb is not enough to order from
Two staircases with the same step count can differ in total length by a foot or more depending on tread depth and riser height, which are rarely identical between homes, especially older builds. Use a stair runner length calculator with your own measured dimensions rather than a generic average when you are ready to order material, since ordering short means a visible seam or a delayed second order.
| Step count | Length range across different tread/riser combos |
|---|---|
| 13 steps | 18.5-21.5 ft (5.6-6.5 m) |
| 16 steps | 22.5-26.5 ft (6.9-8.1 m) |
Landings and turns add length beyond the simple formula
A half landing typically adds 3-6 ft (0.9-1.8 m) depending on its depth, and this is on top of the straight-flight calculation, not included in it.
Ordering guidance
- Count your steps and measure tread depth and riser height at two or three points.
- Multiply per-step total by step count for raw length.
- Add 8-12% waste for a straight flight, more for turns or patterned repeats.
- Confirm the final cut length with your supplier before approving the order.
Whatever you decide, get the numbers first: the stair runner calculator doubles as a stair runner length calculator, adding nosing wrap, landings, winders, pattern repeat and waste so you order the right length the first time.
Frequently asked questions
How long is a stair runner for a 13-step staircase?
Typically 18.5-21.5 ft (5.6-6.5 m) including a waste allowance, based on standard tread and riser dimensions; exact length depends on your measured step size.
Do all staircases use the same tread and riser size?
No, dimensions vary by build era and country, typically 9.5-12 in (24-30 cm) tread depth and 6.5-8.25 in (16.5-21 cm) riser height, so measuring your own stairs is essential.
How much extra length should I add for waste?
8-12% for a straight flight with a plain material or repeat, rising to 12-18% for a flight with a landing or turn.
Does a runner with a landing need much more length?
Yes, typically 3-6 ft (0.9-1.8 m) more than the same step count without a landing, depending on the landing's depth.
Can I estimate length just by counting steps?
Only roughly. A stair runner calculator using your actual tread depth and riser height gives a far more reliable figure than counting steps alone.
What is a good average length to budget for planning purposes?
For early budgeting before final measurement, 1.5 ft (0.46 m) per step including waste is a reasonable planning average for standard residential stairs.
Know your numbers in 30 seconds
Enter your step count, tread depth and riser height — the stair runner calculator gives you the exact length to order, in metres and feet, with waste included.
Calculate my exact lengthEvery guide is written from hands-on measuring and fitting experience, checked against the calculator’s own maths, and re-reviewed whenever prices or methods change. Read our editorial standards.