Measuring a straight stair runner

A straight flight is the one staircase where the arithmetic is genuinely simple: every step is identical, the runner travels in one line, and there are no turns to allow for.

Length = steps × (tread + riser), plus any measured nosing allowance and waste. Add landing travel or a fixed fitting allowance if your runner needs them.

Your staircase

Optional starting measurements

Example measurements only, not building-code advice. Replace them with measurements from your own stairs.

Check a few steps before using one set of measurements for the whole flight.

Number of stairs

Count the tread-and-riser pairs the runner will cover. Exclude landings.

Tread depth (in)

Measure the runner path across the flat tread. Fractions like 10 1/2 work.

Riser height (in)

The vertical face between two treads.

Waste allowance

Custom%

10% is the starting allowance here, not a guarantee. Ask your fitter about patterns and turns.

Add a nosing / overhang allowance per step

Enter the extra runner path around the edge, including any underside wrap. Do not add it twice if it is already included in your measurements.

Your runner estimate

20 ft 3.1 in

Total runner required for 13 steps, including a 10% waste allowance.

Total runner length in each unit
Inches	243.1 in
Feet	20.26 ft
Feet & inches	20 ft 3.1 in
Yards	6.75 yd
Meters	6.17 m
Centimeters	617.47 cm

Length to order

21 ft

7 yd · 6.4 m · 252 in

This calculator provides an estimate based on the measurements and installation assumptions you enter. Complex, curved or winder staircases may require professional measurement.

One step, shown in profile

Side elevation of a staircase. The runner travels across each tread and down each riser, so every step consumes tread depth plus riser height of material.

Measure three steps, not one

Even on a straight flight, treads vary by a few millimetres. Measure the third, middle and second-from-top step and use the largest value — running short is far worse than a small offcut.

Watch the bottom step

Bullnose and curtail bottom steps are wider and deeper than the rest and often take a separately cut piece. Measure it on its own and add it rather than averaging it into the flight.

Straight stairs suit a single piece

With no turns, a straight flight can usually take one continuous runner, which looks better and installs faster. Only the roll length limits you.

Questions people ask

What is the formula for a straight stair runner?: Number of steps × (tread depth + riser height), plus any nosing allowance and waste percentage.
Do straight stairs need extra length?: Only for nosing wrap and waste. There are no turns or winders to allow for, so 5 to 10% is usually enough.

Related guides

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