How to Measure Your Stairs for a Runner

Installing a stair runner can add style and safety to your staircase. This guide will help you measure your stairs accurately for installation techniques.

Getting the measurements right is the most important step in the whole process. Buy too short, and you're left with a runner that barely covers the tread. Buy too long, and you're trimming a handwoven piece that deserves better. This guide will walk you through everything you need to know before you order, including the two things that determine your approach: the type of stairs you have, and the installation method you prefer.

Take both of those decisions before you pick up a tape measure. It will make the rest of this considerably easier.

Step One: Know Your Stair Type

Most staircases fall into one of three categories, and each one is measured slightly differently.

Straight stairs are the most straightforward: a consistent tread depth, a consistent riser height, no turns. If this describes your staircase, measuring is simple arithmetic.

Nosed stairs have a tread that overhangs the riser below it. That overhang, called the nosing, wraps either to a flat squared edge or a rounded bullnose profile. It matters because the installation method you choose will determine how you account for it in your measurements.

Winder stairs change direction as they ascend, with one or more steps taking on a wedge or irregular shape to accommodate the turn. These require a bit more patience to measure, but the principle is the same.

Step Two: Choose Your Installation Style

For straight stairs, this decision is largely aesthetic. For nosed stairs, it determines how you measure.

Hollywood Style

In a Hollywood installation, the runner wraps closely around the nosing, following its profile down onto the riser. The result is a tailored, fitted look that emphasises the shape of each step. It suits both squared and bullnose nosing profiles, but each requires a slightly different measuring approach, described below.

Waterfall Style

In a Waterfall installation, the runner falls straight over the front edge of the tread and drops directly down the riser without wrapping. The effect is softer and more relaxed, with the fabric hanging in a gentle cascade. This method works well with bullnose nosing and tends to be somewhat easier to install.

If your stairs have no nosing at all, the distinction between these two methods largely disappears. Measure tread plus riser, multiply by the number of steps, and add a small allowance.

How Wide Should Your Runner Be?

The standard guidance is to leave around four inches of bare stair visible on each side of the runner. On a typical 36-inch-wide tread, that points to a runner somewhere in the region of 27 to 28 inches wide.

That said, this is a starting point, not a rule. The right width depends on three things: the actual width of your treads, the widths available for the runner you want, and the visual weight of the pattern. A densely patterned kilim, for instance, may read better with slightly more stair showing on each side, giving the design room to breathe. A narrower or more geometric piece might benefit from a tighter fit.

Measure your tread width carefully, then work outward from there.

 

Measuring Straight Stairs

You will need: a tape measure, something to write with, and a calculator if you prefer not to do the arithmetic in your head.

1.      Count the number of steps that will receive the runner. If you are including the top landing, note that separately.

2.     Measure the tread depth: from the front edge of the step (not including any nosing overhang) to the back wall or riser. Write this down.

3.     Measure the riser height: from the top of one tread to the top of the tread above it, measured vertically.

4.     Add the two figures together. This gives you the length of runner needed per step.

5.     Multiply by the number of steps to get your base total.

6.     Add 5% to the total for adjustments, slight variations in step dimensions, and the small allowance needed at the top and bottom of the run.

Example: A staircase with 12 steps, each with a 10-inch tread and a 7-inch riser. 10 + 7 = 17 inches per step. 17 x 12 = 204 inches. Adding 5%: approximately 214 inches, or just under 18 feet.

Measuring Nosed Stairs

The nosing adds length to your measurement because it has to be accounted for in whichever direction the runner travels. The method below differs depending on whether your nosing is squared or bullnosed, and which installation style you have chosen.

Hollywood Style, Squared Nosing

With a squared nosing, the runner folds around a right-angle edge. Measure in two sections.

1.      Place the end of your tape measure at the point where the nosing begins to project from the riser face. Extend the tape to the outermost edge of the nosing. Note this figure.

2.     From the underside of the nosing, measure down to the bottom of the riser. Note this figure.

3.     Add the two measurements together. This is the length of runner required per step.

4.     Multiply by the number of steps, then add 5%.

Hollywood Style, Bullnose Nosing

A bullnose nosing has a rounded profile, so the runner curves rather than folds. The measurement is taken in the same two sections.

1.      From the point where the nosing begins to project, measure over the curve to where the riser face begins. Note this figure.

2.     From the base of the nosing curve, measure down to the bottom of the riser. Note this figure.

3.     Add the two measurements and multiply by the number of steps, then add 5%.

Waterfall Style

In a Waterfall installation, the runner drops straight from the edge of the tread to the base of the riser, without wrapping the nosing profile. This simplifies the measurement.

1.      Place your tape measure at the front edge of the tread, at the outermost point of the nosing.

2.     Let the tape fall straight down to the bottom of the riser. Note this figure.

3.     Add the tread depth (measured from behind the nosing to the back of the step) to the riser drop measurement.

4.     Multiply by the number of steps, then add 5%.

Measuring Winder Stairs

Winder stairs require you to treat the straight steps and the angled steps as separate calculations, then combine them.

1.      Measure the straight steps as described above: tread depth plus riser height, multiplied by the number of straight steps.

2.     For each angled winder step, measure along the outer (widest) edge of the tread, from the front edge down over the riser to the step below. This gives the longest measurement that section of runner will need to cover.

3.     Add 6 to 12 inches per turn to account for the curvature and ensure the runner lies flat through the transition.

4.     Add all sections together, then apply the 5% allowance.

If your winder steps vary significantly in depth or angle, measure each one individually rather than averaging. The outer edge measurement is the one that governs.

A Note on Pattern Repeat

If you are ordering a patterned runner, whether a kilim, a Oushak, or any piece with a repeating geometric or floral motif, the pattern repeat adds a further consideration. Depending on where the installer begins the run, you may need additional length to ensure the pattern falls symmetrically on the tread, or starts and ends at a visually sensible point. For a runner with a repeat of, say, 12 inches, you may need to add up to one full repeat to your total to give the installer flexibility. Ask about the repeat length when you order, and factor it in before you finalise your figures. This is particularly relevant for handwoven pieces, which may have slight natural variation in their repeat due to the way they are made. It is one of the things that makes them worth the consideration.

If Your Stairs Are Not Uniform

Older homes in particular often have stairs that vary slightly in tread depth or riser height from step to step. This is not unusual, and it does not complicate the measurement significantly, but it does mean that averaging is not reliable. The safest approach is to measure at least three steps at different points on the staircase: near the bottom, the middle, and the top. If the figures vary, use the largest tread depth and the largest riser height as your baseline, and measure every step individually if there is meaningful variation throughout. The 5% allowance built into these calculations is specifically designed to absorb small variations of this kind. For staircases with significant irregularity, rounding up to the nearest half-foot of runner length is a sensible precaution.

Rug Pad and Installation Thickness

If you plan to use a rug pad beneath the runner, account for it before you finalise your tread measurement. A pad of any thickness, typically between a quarter and a half inch for stair use, will reduce the effective depth of the tread by pushing the runner fractionally forward. On most staircases this is negligible, but on shallower treads it is worth noting. For Hollywood-style installation in particular, where the runner wraps the nosing closely, a thicker pad can also affect how cleanly the fabric folds. Thinner, firmer pads tend to work better in this situation.

Before You Order

Double-check every measurement at least once, ideally on a different day from when you first took them. Small errors compound over twelve or fourteen steps. Consult with the stair runner installer for any specific measuring requirements they may have.

If you are ordering one of our handwoven runners and are uncertain about your calculations, get in touch before you place the order. We can talk through your staircase type, the installation method you have in mind, and the width options available for the piece you want. Getting this right at the start is much simpler than resolving it afterwards.

Browse our stair runners collection at kilim.com, or contact us directly if you would like guidance on a specific piece.