How to Measure Stairs for a Runner

What you need before you start

• A steel tape measure — cloth tapes sag and under-read on deep treads.
• A notepad or your phone — record every step separately, not one average.
• A torch — nosing overhangs and the back of treads hide in shadow.
• A helper for anything over about 14 steps, or for curved flights.
• Your unit decided up front — work in inches or centimetres, never a mix.

Know the parts of a staircase

1.Measure a single tread

The tread is the horizontal surface you stand on. Measure it front to back at the deepest point, running the tape from the very front edge of the nosing to where the tread meets the riser behind it. Most tread depths land between 9in and 11in (23–28cm).

Check two or three steps, not one. Older homes vary by half an inch or more, and the bottom step is often deeper or wider than the rest. Always build your total on the largest measurement you find — surplus is trimmable, shortfall is not.

2.Measure a single riser

The riser is the vertical face underneath the next tread. Measure from the surface of one tread straight up to the surface of the next. Typical riser heights are 7in to 8in (18–20cm). Open-riser staircases still need this figure, because the runner drops the same vertical distance whether there is a board behind it or not.

Add tread and riser together and you have the length one step consumes. A 10in tread with a 7.5in riser uses 17.5in — about 1.46ft, or 0.445m — per step.

3.Count your steps properly

Count every riser, including the one up onto the landing at the top. A staircase described as “13 steps” usually means 13 treads and 14 risers, so recount rather than trusting the description or an old quote.

Decide too where the runner starts and stops. Many installations skip the bottom riser entirely if the first step is a bullnose or curtail step, and some stop one step short at the top where a landing rug takes over. Write down the first and last step numbers so your count and your fitter's count agree.

4.Decide waterfall or wrapped nosing

A waterfall installation lets the runner fall straight from the nosing to the next tread, leaving a small void behind. It is quicker, uses less material and suits thick or textured runners. A wrapped (or “Hollywood”) fit hugs the curve of the nosing lip, showing the shape of every step. It looks sharper and is the usual choice for patterned wool runners, but it needs an extra inch or two per step.

5.Measure landings and winders separately

Landings are measured end to end in the direction the runner travels, from the top nosing of the flight below to the first nosing of the flight above. Do not forget the riser at each end of the landing — those are separate vertical drops.

Winder steps — the pie-shaped steps on a turn — must be measured at their widest point, because the runner has to span the full width there. Number them on your sketch (W1, W2, W3) and record each one's widest depth and its width at both the narrow and wide ends. Fitters cut winders as individual pieces, so an average is not good enough.

6.Check the width and reveal

Measure the narrowest step, usually somewhere in the middle of the flight or at the narrow end of a winder. Subtract the reveal you want each side and choose the nearest stock width below that figure.

An even reveal matters more than a wide one. If your stringers are not parallel — common in period homes — centre the runner on the narrowest point so the taper is shared between both sides instead of piling up on one.

7.Add pattern repeat and waste

Patterned runners have to line up across every step, so allow one full pattern repeat per flight. Then add a waste margin on top of everything: 10% for a plain straight flight, 15% when there is a pattern to match, and up to 20% for winders, curves or multiple landings.

Finally, round up to how the supplier sells it. Most sell in whole metres or feet from a roll, so a 6.4m requirement becomes a 7m order. Buy the full quantity in one go — a second cut ordered later rarely matches the original dye lot.

Worked example: a 13-step staircase with one landing

Thirteen steps at a 10in tread and 7.5in riser, wrapped nosings, one 36in landing with a 7.5in riser at each end, a plain runner and a 10% waste margin.

Change the nosing finish to waterfall and you save 19.5in. Add a patterned runner with a 24in repeat and you add roughly 24in back per flight. Small decisions move the order by a metre or more, which is exactly why it is worth running the numbers before you shop.

Inches, feet, metres: converting without errors

Pick one unit and stay in it until the very last step. Mixing centimetres for treads with feet for landings is the most common source of a wrong order — the stair runner calculator converts everything for you and shows both units side by side.

Special staircases

• Curved or spiral flights. Measure the outer edge of every tread, not the centre line. The runner follows the longest path and each step is cut individually.
• Bullnose or curtail bottom step. Usually treated as its own piece, or skipped entirely. Measure it separately and decide with your fitter.
• Open-riser stairs. Still count the riser height; the runner drops the same distance and often wraps the tread underside.
• Split or double flights. Treat each flight as a separate piece with its own pattern repeat, then total them.
• Stairs with a half-landing turn. Measure the landing in both directions and use the travel path the runner actually takes around the turn.

Seven measuring mistakes that cost money

• Measuring one step and assuming all the others match.
• Forgetting the top riser onto the landing.
• Ignoring the nosing overhang on a wrapped installation.
• Averaging winder steps instead of measuring each at its widest point.
• Measuring over old carpet and gripper, then finding bare treads are deeper.
• Leaving out the pattern repeat, so the design steps out of alignment halfway up.
• Ordering the exact calculated figure with no waste margin at all.

Your measuring checklist

• Tread depth at the deepest point (check 3 steps) ▢
• Riser height (check 3 steps) ▢
• Tread count and riser count, recorded separately ▢
• Waterfall or wrapped decided, with the wrap allowance ▢
• Each landing measured end to end, plus its risers ▢
• Every winder measured at its widest point and numbered ▢
• Narrowest stair width, and chosen reveal ▢
• Pattern repeat length from the product page ▢
• Waste margin chosen (10 / 15 / 20%) ▢
• Sketch photographed and saved ▢

Frequently asked questions about measuring stairs for a runner

Turn your measurements into a length

Ready to add it all up? Use the free stair runner calculator, check the stair runner cost guide, size your reveal with the stair runner width calculator, or browse every tool on the stair runners hub.