Why the going matters for runners
While the going sounds like a simple measurement, it dictates how much carpet you need for every single step. In my experience, even a small difference of 1-2 cm in tread going can add up to half a metre of extra runner needed over a full flight. More importantly, if your going is too short, the stair becomes steep and difficult to navigate, and carpet fitters have less surface area to fix the runner down securely.
How much runner do I need?
For a 13-step flight with a 10 in going: 10 in going + 7.5 in rise + 0.75 in nosing wrap = 18.25 in per step. Total = 237.25 in (19.8 ft). Plus 2 ft for turns = 241.25 in (20.1 ft). With 10% waste, you need about 22.2 ft.
In UK metric: 25 cm going + 19 cm rise + 2 cm nosing = 46 cm per step. Total = 598 cm. Plus 60 cm for finish = 658 cm (6.58 m). With 10% waste, you need about 7.25 m.
| Measurement | US (in) | UK (cm) |
|---|---|---|
| Going | 10 in | 25 cm |
| Rise | 7.5 in | 19 cm |
| Per step | 18.25 in | 46 cm |
| Total for 13 steps | 237.25 in | 598 cm |
| With waste (10%) | 261 in | 658 cm |
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 calculatorConsistency is key
On a well-built staircase, every tread going should be identical. If you measure differences of more than 5mm across the flight, your stairs are poorly constructed and may be a trip hazard.
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
What is the going of a stair?
It is the horizontal distance between the faces of two consecutive risers.
What is the minimum going for UK stairs?
Generally 220mm for private stairs, though this can vary by building type.
Why does going affect runner length?
The longer the going, the more carpet you need to cover each step, which adds up quickly over the whole flight.
Does going affect runner safety?
Yes, if the going is too shallow, it's easy to slip, and the runner will have a steeper drop that needs extra care during installation.
How do I measure the going?
Measure from the face of one riser horizontally to the face of the riser above it.
Can a stair going vary?
No, a professional staircase should have consistent going across all steps for safety.
Does a small going need special carpet?
Not necessarily, but you may want a thinner, more flexible runner to ensure it wraps the nosing effectively on a tighter step.
Can I use the calculator to check if my stairs meet standards?
The calculator helps with sizing, but always consult your local building code for safety compliance.
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.
Size your runner correctly with our 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.