Why area calculations are tricky
Carpet runners aren't just one big rectangle. They're a series of connected rectangles (treads and risers) that follow the 3D shape of your stairs. Simple square-footage math fails here because it doesn't account for the nosing wrap, the tucks, and the extra needed for landings. This calculator integrates these 3D requirements to give you a true area-equivalent length.
| Element | Area Calculation |
|---|---|
| Treads | Width * Depth |
| Risers | Width * Height |
| Landing | Width * Length |
| Waste Margin | 10-20% |
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
Is this calculator accurate for complex stairs?
It's great for estimation; for complex turns, always add a 20% waste buffer.
Why calculate area instead of just length?
Some retailers sell carpet by square metre, and this helps with price comparison.
Does area account for waste?
The calculator helps identify net area; you must manually add the waste factor.
Is area calculation better for wide runners?
Yes, wide runners rely heavily on surface area, and this provides a clear metric.
Can I use this for stair rods?
This is for carpet area only; rods are purchased based on stair width.
What's the difference between area and length?
Length is for ordering runners; area is for comparing price per square metre.
Is it harder to fit wide runners?
Yes, wide runners need more secure fixing across the entire width.
How do I measure for area if stairs are tapered?
Measure the widest part of each tread to ensure full coverage.
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 stair runner 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.