The arithmetic behind 13 steps
One step takes the tread depth plus the riser height plus the nosing: 10in + 7.5in + 1in gives 18.5in of carpet run. Thirteen of those is 240.5in, or 6.68 yards of travel down the flight. Multiply by a 36in (1 yard) stair width and you get 6.68 square yards of bare coverage. Add 10 per cent for waste and you are at 7.4 square yards for a runner-width stair, and closer to 12 to 14 square yards once you carpet wall to wall on a wider staircase and allow for the cutting pattern off the roll.
| Stair width | Bare coverage | With 10% waste | Linear yards off 12ft roll |
|---|---|---|---|
| 27in (runner) | 5.0 sq yd | 5.5 sq yd | 1.5 |
| 36in | 6.7 sq yd | 7.4 sq yd | 2.0 |
| 42in | 7.8 sq yd | 8.6 sq yd | 2.5 |
| 48in | 8.9 sq yd | 9.8 sq yd | 2.5 |
| 36in + landing | 9.7 sq yd | 10.7 sq yd | 3.0 |
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 suppliers quote more than the maths says
The table above is coverage. What you buy is roll. Broadloom comes 12ft or 15ft wide, and stair pieces are cut across the roll so the pile runs the right way down every step — which means a 36in stair uses a 36in-wide strip of a 144in roll and the rest of that strip is only usable if the fitter has somewhere else to put it. On a stairs-only job with no adjoining rooms, expect the invoice to reflect closer to 12 to 14 square yards of purchased material for a 13-step flight, even though the carpet on the stairs is 7.
Landings, winders and the bottom step
A half landing at 900mm square adds about 1 square yard. A quarter turn of three winders adds roughly the same again, because each wedge is cut to its widest point. A bullnose bottom step adds 200mm to 300mm of run over a plain step and needs its own piece. None of these are large on their own; together they routinely add 25 per cent to a job that was quoted from the step count alone.
What it costs
At mid-range carpet prices, the material for 13 stairs lands between 300 and 700 in most currencies, with fitting adding a per-step charge on top. Fitters commonly price stairs per step rather than per yard because the labour, not the material, is what makes stairs expensive: every step is a separate cut, a separate tuck and a separate set of fixings.
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.
Still deciding on material, width or pattern? Our hub on stair runners compares weaves, widths, backings and fitting styles side by side, then hands the numbers straight to the calculator.
Frequently asked questions
How many square yards of carpet for 13 stairs?
Around 12 to 14 square yards of purchased material for a standard 36in flight, from about 6.7 square yards of actual coverage. The gap is roll waste — stair pieces are cut across a 12ft roll and the offcut is rarely usable elsewhere.
How many linear yards do I need for 13 stairs?
About 2 linear yards of 12ft broadloom for the coverage itself, but order closer to 6 if the fitter cannot use the offcuts on an adjoining landing or room. Ask your fitter how they intend to cut it before ordering.
How much carpet for 13 stairs and a landing?
Add roughly 1 square yard per square metre of landing. A typical 900mm square half landing takes a 13-step flight from about 7.4 to about 10.7 square yards including waste.
Is a runner cheaper for 13 stairs?
Yes, usually by 25 to 40 per cent on material, because a 27in runner on a 36in stair covers about three-quarters of the area. Fitting costs are similar per step, so the saving is mostly in the carpet itself.
Does the number of steps include the landing?
Usually not. Thirteen steps normally means 13 risers and 12 treads plus the upper floor, so count risers when you order and measure the landing as a separate rectangle.
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.
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Every 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.