Measure every tread, not just one
Staircases are rarely perfectly parallel. Measure the tread width at the narrowest point, usually the top or bottom step where skirting or a newel post intrudes, and use that figure as your governing width.
Reveal margins
| Reveal each side | Look | Best for |
|---|---|---|
| 2 in (5 cm) | Traditional, generous stained-wood border | Period staircases |
| 3 in (7.5 cm) | Balanced, most common choice | Most homes |
| 4-5 in (10-12.5 cm) | Runner reads as narrow, modern | Wide treads, contemporary schemes |
Worked example
A tread measuring 38in (96.5cm) wall to wall with a 3in (7.5cm) reveal each side needs a 32in (81cm) runner, which is the closest stock width. On a 36in (91cm) tread with the same reveal you land close to 30in (76cm), so most suppliers would round down to 27in for a slightly larger reveal or up to 32in for a smaller one.
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 calculatorStandard stock widths
| Stock width (in) | Metric equivalent | Typical tread it suits |
|---|---|---|
| 22 in | 56 cm | Narrow cottage stairs |
| 27 in | 68 cm | Standard flight, 33-39in tread |
| 32 in | 81 cm | Wider flights, 38-44in tread |
| 36 in | 91 cm | Grand or open-plan staircases |
- Measure at least three points along the flight: top, middle, bottom.
- Account for handrail brackets or radiators that intrude on width.
- Round down to the nearest stock width if you are between sizes and prefer a larger reveal.
- Custom widths are available but cost 15-30% more than stock sizes.
Winders need special care
On winder or curved stairs the tread width changes across the turn. Measure each winder individually rather than assuming the straight-flight width carries through.
Worked example with real numbers
To see how how to measure a stair runner for width plays out on an actual staircase, take a common 13-step flight with a 10 in (25 cm) tread depth and a 7.5 in (19 cm) riser height. That gives 17.5 in (44 cm) per step, or 227.5 in (5.78 m) of raw length before any waste allowance is added, a figure worth keeping in mind whenever this topic is discussed in isolation from the rest of the job.
| Measurement | Imperial | Metric |
|---|---|---|
| Tread depth | 10 in | 25 cm |
| Riser height | 7.5 in | 19 cm |
| Per step total | 17.5 in | 44 cm |
| 13 steps, raw length | 227.5 in | 5.78 m |
| With 8% waste allowance | 245.7 in | 6.24 m |
When to call a professional instead
Plenty of homeowners handle how to measure a stair runner for width themselves on a straightforward straight flight, but certain conditions tip the balance firmly towards hiring a fitter. Getting a second opinion before committing materials often costs nothing and can save an expensive mistake on a job that cannot easily be undone.
- The staircase has a turn, winders, a curve or a split level rather than one straight run.
- The existing substrate is damaged, damp, or its condition is genuinely unclear.
- The runner is an expensive natural fibre or bespoke pattern where a cutting mistake is costly.
- You have no experience with a staple gun, knee kicker or carpet seaming on stairs.
- The staircase is the main one in the home and downtime or an unfinished look is not acceptable.
Getting the best result long-term
A stair runner that is measured, ordered and fitted correctly on day one keeps paying off for years: it wears evenly, stays flat at the nosing, and does not need premature replacement. When working through how to measure a stair runner for width, treat the first measurement and the final fitting check as equally important, since a good spec undone by a rushed fit still ends in an early failure.
- Keep a written record of every measurement, the supplier, and the exact spec ordered, in case you need to reorder a matching piece later.
- Ask your fitter to leave any offcut, it is useful for patching a worn tread years down the line.
- Photograph the staircase before and after fitting so you have a reference for insurance or resale.
- Revisit fixings and edges once a year even on a well-fitted runner, since timber stairs move seasonally with humidity.
Extra buying tips worth knowing
A little extra homework before ordering saves both money and disappointment on how to measure a stair runner for width. Suppliers vary widely in how clearly they explain pricing, lead times and what happens if a measurement turns out to be wrong once the crew arrives.
| Question to ask supplier | Why it matters |
|---|---|
| Is remeasuring included before cutting? | Protects you if your DIY measurement was slightly off |
| What happens if the runner is too short on the day? | Some fitters carry matching offcuts, others do not |
| Is old carpet removal and disposal included? | Often a separate line item that is easy to miss |
| What is the aftercare/warranty policy? | Covers seam failure or edge fraying within the first year |
A quick pre-order checklist
Before you place an order relating to how to measure a stair runner for width, run through a short checklist to catch the errors that cause the most reorders and delays. A few extra minutes here is far cheaper than a wrong cut of carpet or a mismatched batch.
- Re-measure the narrowest tread and the total flight length a second time on a different day.
- Confirm the dye lot or batch number matches across all rolls if more than one is needed.
- Check the supplier's stated waste allowance is included, not assumed.
- Agree a fitting date only once the material has actually arrived and been inspected.
- Keep the invoice and batch details safe in case a repair or extension is needed later.
Common measuring mistakes to avoid
Even careful DIYers repeat the same handful of errors when working out how to measure a stair runner for width. Knowing them in advance is the fastest way to avoid a reorder or an awkward-looking fit.
| Mistake | Consequence | Fix |
|---|---|---|
| Measuring only the top step | Runner too wide for a narrower step further down | Measure at least three points, use the narrowest |
| Ignoring handrail brackets | Runner edge catches on hardware | Measure clear width between obstructions |
| Assuming symmetric reveals | Runner looks off-centre on an uneven staircase | Check both walls independently at each tread |
| Ordering stock width without checking tread width first | Reveal ends up too tight or too wide for the look wanted | Calculate reveal from actual tread width before choosing stock size |
Metric vs imperial confusion
Many suppliers list stock widths in inches while customers measure in centimetres, or vice versa, and small rounding errors compound over a 13-step flight. Convert your measurement once, write both figures down, and use that pair consistently through ordering and fitting rather than converting back and forth each time.
How suppliers cut and bind custom widths
When a stock width does not suit the staircase, a supplier cuts broadloom carpet to the exact figure from your how to measure a stair runner for width calculation and binds or serges the raw edges to stop fraying. This typically adds a working day or two to the order and a modest premium, but it avoids compromising on reveal size purely to fit a standard roll.
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 often should a stair runner be professionally reviewed?
Once a year is sensible even if nothing looks wrong, since fixings loosen and timber treads move slightly with the seasons, and catching a lifted edge early prevents a trip hazard.
Should I keep the offcut after fitting?
Yes, ask your fitter to leave any offcut from the same dye lot. It is the only reliable way to patch a worn or damaged section later with an exact colour and pattern match.
Do I need to remeasure if my staircase has a turn?
Yes. Winders and turns change the usable tread width across the flight, so measure each affected step individually rather than relying on the straight-run figure.
What width stair runner do I need?
Measure your narrowest tread wall to wall, then subtract twice your intended reveal (commonly 2-4in per side). Round to the nearest stock width: 27in, 32in or 36in are the most common.
Is 27 inch or 32 inch runner more standard?
27in (68cm) is the most common width in the US and UK, suiting treads around 33-39in wide with a 3in reveal each side. 32in suits wider treads.
Should I measure the tread or the staircase width?
Measure the tread itself, wall to wall or wall to spindle, at its narrowest point. Do not measure the overall staircase opening, which can be wider than the usable tread.
Can a stair runner be custom width?
Yes, most suppliers cut broadloom carpet to any width and bind the edges to order, typically at a 15-30% premium over stock runner widths.
What is the biggest mistake people make with this?
Rushing the measuring or prep stage. Most poor outcomes with how to measure a stair runner for width trace back to a single measurement taken at the wrong point, or a substrate check skipped to save a few minutes, both far cheaper to fix before the runner is cut than after.
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.