Getting your measurements right
The first step in ordering online is taking accurate measurements of your staircase. Most people simply measure the length of the stairs but forget to add extra for the nosing wrap, which is the carpet wrapping around the edge of each tread. On a standard flight, you also need to account for the thickness of your underlay and ensure your measurements account for any winders or curves. When using the stair runner calculator, you can enter your exact tread and riser dimensions to see exactly how much length is required. If your staircase has winders, it is often best to consult a professional to ensure your measurements are precise, as even a small error on a curved step can lead to significant issues with pattern alignment and length.
Once you have your core measurements, consider the width. Stair runners come in fixed widths. If your staircase is 36 inches wide, you might want a 30-inch runner to leave a 3-inch gap on each side. Always ensure the runner width you are ordering matches your desired stair runner gap perfectly. Remember that some runners, especially natural fibres, can have slight width variations across the roll. If you are aiming for a very specific gap, it is always wise to double-check the width tolerance with the supplier before you order.
How much runner do I need?
For a 13-step flight, the calculation starts with the individual step. A 10 in tread run plus a 7.5 in riser height plus a 0.75 in nosing wrap brings the total per step to 18.25 in. Over 13 steps, this is 237.25 in. We then add a 12 in finishing allowance for the top and bottom of the flight to tuck the runner under the landing and finish at the base, bringing the total length to 261.25 in, or 21.77 ft. Adding an 8% waste margin for standard fitting, you arrive at approximately 23.5 ft. Metric: 25 cm + 19 cm + 1.9 cm = 45.9 cm per step. Over 13 steps, this is 596.7 cm, plus 60 cm for finishing, total 656.7 cm, plus 8% waste, total approx 7.1 m.
| Step | US (in/ft) | UK (cm/m) |
|---|---|---|
| Per-step total | 18.25 in | 45.9 cm |
| 13 steps | 19.77 ft | 5.97 m |
| Finishing | 21.77 ft | 6.57 m |
| With 8% waste | 23.5 ft | 7.1 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 calculatorUnderstanding fibre and durability
When you browse for stair runners online, look closely at the fibre type and construction. Nylon is a workhorse that bounces back from heavy foot traffic, while wool offers a luxurious, traditional feel with excellent longevity if cared for. Avoid low-density synthetics if you have a busy household; they will mat and wear thin within a couple of years. For more guidance on choosing the right material, check out our guide on stair runners for busy homes.
Samples are essential
Before ordering any stair runner, order at least 3-5 samples. Seeing the colour and feeling the texture in your home's natural light will save you from an expensive mistake. You cannot accurately gauge colour from a monitor.
Finally, check the lead times and shipping policies. If you are having a fitter come out, ensure the runner has arrived and been inspected at least a week before they are booked. If the runner arrives with a defect or is the wrong colour, you will need that time to sort it out without losing your fitter's slot.
In summary, ordering online is a straightforward process if you are methodical. Take your time measuring, use our tool to verify your numbers, and always get samples before you commit.
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
Can I measure my own stairs?
Yes, provided you are thorough and include all necessary allowances for the nosing and finishing.
What is the most important measurement?
The nosing wrap is often overlooked, so make sure you include that for every step.
How do I ensure the colour is correct?
Samples. Never skip ordering samples before making your final decision.
Can I order by the foot?
Yes, many suppliers sell by the linear foot or meter, which gives you more control over the exact length.
What should I do if the order is delayed?
Contact the supplier immediately and get an updated delivery date in writing.
Is stair runner installation included?
Almost never. You will need to hire a professional carpet fitter separately.
Do I need an underlay?
Yes, it's non-negotiable for a professional installation and long carpet life.
How do I know if the runner is high quality?
Check the density of the weave, the reputation of the manufacturer, and whether it is designed for heavy-duty stair use.
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.
Plan your order 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.