Stair Runner Measuring Checklist: 10 Steps to Get It Right

1. Count the steps twice

Start by counting the steps from the bottom of the flight to the top landing, then count again from the top down, since it's surprisingly easy to lose count on a longer staircase or double-count a winder that spans two positions. Note whether the top landing itself needs covering as part of the run or is a separate piece, since this changes the total length calculation and is easy to overlook if you only think of “the stairs” as the sloped section.

2. Measure tread depth on every step

Tread depth, sometimes called the “going,” is the horizontal distance from the front edge (nosing) of one step to the front edge of the step above it. Measure this on at least three or four steps rather than assuming they're identical, since older staircases especially can vary by half an inch or more between steps, and that variation compounds across a full flight if you only measure once and multiply.

3. Measure riser height on every step

Riser height is the vertical distance from one tread surface to the next. Like tread depth, measure several risers rather than one, particularly near the top or bottom of the flight where a builder sometimes adjusts the final step height slightly to make the total flight height work out evenly against the floor above.

4. Add a nosing wrap allowance

The nosing is the rounded or bullnosed front edge of the tread, and the runner needs a small extra allowance to wrap around it cleanly rather than sitting flat and pulling taut at the edge. A standard allowance is 0.75 in (1.9 cm) per step for a typical rounded nosing, though a squared-off or minimal nosing might need slightly less and a deep, heavily rounded nosing might need slightly more.

5. Check stair width before choosing runner width

Measure the full width of the staircase at several points along the flight, not just at the top, since older stairs can taper very slightly or have a skirting board that protrudes more at the bottom. Common runner widths leave a consistent margin of exposed tread on each side, typically 3-4.5 in (7.5-11 cm) per side on a 36 in (91 cm) wide staircase, so knowing your actual stair width tells you what runner width will look proportionate.

6. Identify any turn, winder or landing

A straight flight is measured with simple per-step arithmetic, but a winder, dog-leg or half-landing needs its own separate measurement and calculation, since the geometry doesn't scale linearly the way straight steps do. Measure a landing by its actual footprint in square feet or metres, and measure a winder tread individually since its depth varies across its width in a way a standard rectangular tread doesn't.

How much runner do I need?

Bringing points 2 through 4 together on a 13-step US flight: a 10 in tread run plus a 7.5 in riser height plus a 0.75 in nosing wrap gives 18.25 in per step. Multiplied across 13 steps that's 237.25 in, or 19.77 ft. Add a top-and-bottom finishing allowance of 12 in each (24 in total) for 261.25 in, or 21.77 ft, then apply a waste margin, 6% for a plain runner or up to 10% for a patterned one, bringing the total to roughly 23.1-23.9 ft depending on the runner style chosen.

In UK metric terms, a 25 cm tread run plus 19 cm riser plus 1.9 cm nosing wrap gives 45.9 cm per step, or 596.7 cm across 13 steps. Add a 60 cm finishing allowance for 656.7 cm, then apply the same 6-10% waste range to land between roughly 6.96 m and 7.22 m depending on whether the runner is plain or patterned.

7. Note the finishing allowance you need at top and bottom

The runner needs extra length at the top to tuck under a landing carpet or wrap around the top nosing, and at the bottom to finish cleanly against the floor or wrap under slightly for a neat edge. A common allowance is 12 in (30 cm) at each end, though this varies depending on whether the top connects to another carpeted area or finishes at a bare floor, so check both ends of your specific flight rather than assuming a standard figure applies everywhere.

8. Confirm the pattern repeat if the runner isn't plain

If you've chosen a patterned or bordered runner, ask the supplier for the exact repeat length before finalising your order, since this determines how much extra waste allowance to apply. A small repeat under 12 in (30 cm) needs less extra allowance than a large, bold repeat, and knowing the figure precisely lets you calculate wastage rather than guessing at a generic percentage.

1. Count the steps twice from both directions
2. Measure tread depth on multiple steps, not just one
3. Measure riser height on multiple steps, not just one
4. Add the correct nosing wrap allowance for your tread's edge profile
5. Confirm stair width at several points along the flight
6. Measure any winder or landing separately by its actual footprint
7. Add a top-and-bottom finishing allowance for tucking and edge finishing
8. Check the pattern repeat length if the runner isn't plain
9. Apply an appropriate waste margin, 5-10% depending on pattern
10. Cross-check the total using a stair runner calculator before ordering

9. Apply the right waste margin for the runner style

A plain, flat-weave runner typically needs a 5-6% waste margin, while a patterned or bordered runner needs 8-10% to keep the design aligned across every step. Applying the wrong margin for your chosen style is one of the most common ordering mistakes, since it's tempting to use a single “standard” percentage for every job rather than adjusting it to the specific material.

10. Cross-check with a calculator before you order

Once you've worked through the first nine points by hand, run the same figures through a stair runner calculator as a final check. This catches simple arithmetic slips, like forgetting to double the finishing allowance for both ends, that are easy to make when adding up nine or ten separate measurements by hand. It only takes a minute and it's much cheaper than ordering short and waiting on a second delivery, or worse, a different dye lot that doesn't quite match the first.

Whether you're a homeowner measuring for the first time or a fitter double-checking a client's own figures, working methodically through all ten points, and mentioning early on to the client that stair runners are measured this precisely, builds confidence that the final order will actually fit the staircase in front of you, rather than a generic average flight that may not match your own.

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.