What makes winders different to measure
Winder steps are the pie-shaped or triangular treads used to turn a staircase around a corner, usually in place of a small square landing, and unlike a straight tread they don't have a single going measurement, the depth changes across the width of the step. Measure a winder at its narrowest point, near the inside of the turn, and you'll get a going of just a few inches, sometimes less than 4 in (10 cm). Measure it at its widest, near the outside wall, and the going can be 15-18 in (38-46 cm) or more. Neither number is what you actually need for sizing a runner.
What matters is the going along the walking line, an imaginary line roughly a third of the way in from the narrow inside edge of the winder, since that's approximately where someone's foot naturally lands when descending the stairs, and it's also the standard reference line building regulations use when assessing winder step safety. Measure your winder's going along this line, at roughly the same distance in from the inside edge on each winder in the set, and you'll get a going figure that's consistent enough to size a runner against.
How much runner do I need?
For a US example, imagine a set of three winders turning a 90-degree corner, each with a walking-line going of 11 in and a riser height of 7.5 in, plus the same 0.75 in nosing wrap per step used on straight treads. That's a per-step total of 19.25 in, and across three winders that's 57.75 in, or 4.81 ft. Because winders are trickier to cut and fit cleanly around the pie shape, and because any pattern needs re-aligning across the turn, apply a higher waste margin here, 15% rather than the 5-7% used on a straight flight, bringing the winder section to roughly 5.5 ft. Add this to your straight-flight totals above and below the winders to get the full staircase figure.
In UK metric terms, the same three-winder turn is 28 cm walking-line going, 19 cm riser, 1.9 cm nosing wrap, for 48.9 cm per step. Across three winders that's 146.7 cm, and with a 15% waste margin for the trickier cutting and any pattern realignment, that comes to roughly 1.69 m for the winder section alone. On a full staircase this gets added to the straight flights above and below the turn, plus any landing sections, to reach the total order length.
| Measurement | US (in/ft) | UK (cm/m) |
|---|---|---|
| Walking-line going | 11 in | 28 cm |
| Riser height | 7.5 in | 19 cm |
| Nosing wrap per step | 0.75 in | 1.9 cm |
| Per-step total | 19.25 in | 48.9 cm |
| 3-winder subtotal | 4.81 ft | 1.47 m |
| With 15% waste margin | 5.5 ft | 1.69 m |
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 calculatorMarking out the walking line before you measure
The easiest way to find a consistent walking line on a real staircase, rather than relying on a rough estimate, is to measure in from the narrow inside edge of the widest part of the winder by a fixed distance, commonly 12 in (30 cm) on a standard-width staircase, and mark that point on each winder tread with a pencil or a strip of masking tape. Once you've marked the walking line on every winder in the set, measure the going along that marked line on each step in turn. This is worth doing even if you're planning to have a professional fitter measure and cut the runner, since it gives you a sanity-check figure to compare against their quote.
- Identify the narrow inside edge and the wide outside edge of the winder set.
- Mark a walking line roughly 12 in (30 cm) in from the narrow edge on a standard-width stair.
- Measure the going along the walking line on each individual winder tread.
- Measure the riser height on each winder as you would on a straight step.
- Add a wider nosing wrap allowance if the winder's nosing profile differs from the straight treads.
- Apply a 12-15% waste margin for the winder section to allow for pattern matching and awkward cuts.
Winders often need a wider runner too
Because a winder tapers, the runner width that looks proportionate on the wide outside edge can look cramped near the narrow inside edge. Many fitters run a slightly wider runner through a winder section than on the straight flight, or accept a smaller margin of exposed tread near the inside edge, to keep the visual width consistent.
Patterned runners on winders need extra planning
If you've chosen a stair runner with a repeating pattern, a stripe, a border, a geometric print, winders are where the pattern is hardest to keep looking continuous, because the tapering shape means the pattern naturally distorts slightly across the turn even with careful cutting. Some fitters deliberately centre the pattern on the walking line and accept a small amount of visible distortion near the edges, since that's less noticeable than an obviously misaligned pattern along the line people actually walk. If pattern continuity through the winders matters a lot to you, mention it to your supplier before ordering, since it may change how much extra length or width they recommend for that section, and it's worth discussing with anyone experienced in fitting stair runners on turned staircases before you commit to a fabric.
Once you've measured the winder section and the straight flights either side, add everything together, including any landing sections, and check the combined total against the stair runner calculator, which lets you enter straight, winder and landing sections as separate inputs rather than forcing you to blend them into one average figure that risks under-ordering the trickiest part of the job.
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
Where exactly do I measure a winder's going?
Measure along the walking line, roughly 12 in (30 cm) in from the narrow inside edge on a standard-width staircase, not at the widest or narrowest point of the tapered tread.
How much extra runner do winders need compared with straight steps?
Winders typically need 10-20% more runner per step than a straight tread of similar going, mainly because of the higher waste margin needed for awkward cutting and, if applicable, pattern matching across the turn.
What waste margin should I use for a winder section?
Use 12-15% for winders, higher than the 5-7% typical of a straight flight, to account for trickier cuts and any pattern realignment needed across the tapering treads.
Can I use a wider runner through a winder section?
Yes, some fitters run a slightly wider runner through winders to keep the visual width looking consistent from the narrow inside edge to the wide outside edge, though this depends on your staircase width and style preference.
Do winders need a different nosing wrap allowance?
If the winder's nosing profile matches the straight treads, use the same wrap allowance. If it's a different profile, common on older converted staircases, measure it separately and adjust the allowance accordingly.
How do patterns behave on winder stairs?
Patterns naturally distort slightly across a tapering winder tread. Most fitters centre the pattern on the walking line and accept minor distortion near the edges, since that's less visually obvious than a misaligned pattern along the walked line.
Should I measure every winder in a set individually?
Yes, even winders that look identical often have small variations in going and riser height, especially in older properties, so measure each one along the walking line rather than assuming they match.
How do I combine winder and straight-flight measurements into one order?
Calculate the straight flights above and below the winders separately, add the winder section's length with its own waste margin, then sum all sections together, including any landings, for your total order length.
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.
Combine your winder and straight-flight numbers with the stair runner calculatorEvery 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.