Why stair pitch matters
Steeper stairs mean more friction on the runner. If your pitch is near the 42-degree mark, the runner is going to see significant shear force whenever someone walks down it. In these cases, using a higher-quality underlay is essential to prevent the carpet from stretching or shifting.
How to measure pitch
You can use a digital level app or a physical level and a tape measure. Measure the total rise and total run, then apply the arctangent formula. If you have the riser and going, the ratio of rise-to-going gives you the angle.
| Pitch Angle | Comfort Level |
|---|---|
| 25-30 deg | Gentle |
| 30-37 deg | Standard |
| 38-42 deg | Steep |
| >42 deg | Very steep/Ladder-like |
Measuring Tip
Place a straight edge on the tread nosings across the whole flight to get a consistent angle measurement.
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 calculatorWhatever 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 a safe stair pitch?
Ideally 30-42 degrees.
Does pitch affect carpet wear?
Yes, steeper stairs increase the force exerted on the runner, leading to faster wear.
Can I measure pitch with a phone?
Yes, many level apps use the internal gyroscope to give a surprisingly accurate angle.
Do steep stairs need special runner fitting?
They benefit from high-quality underlay and firm fixing points to withstand the added force.
How does pitch affect runner sizing?
Steeper stairs use more runner material because the distance between tread and riser effectively increases.
What if my pitch is too high?
You may need to ensure handrails are firm and runners are properly secured for safety.
Can the calculator help me plan the installation?
Yes, it helps you estimate material and identify if you need extra support for the runner.
Is stair runner carpet slippery on steep stairs?
With the right backing and underlay, it shouldn't be, but a high-grip runner is always recommended.
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.
Calculate your runner requirements 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.