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How to Measure for A Basic Handrail Installation

Measuring for a stair railing is a fairly simple task yet still requires precision to provide reliable support and optimal fall prevention. Knowledge of a few basic building code requirements and an understanding of what to measure will remove much of the stress that generally accompanies building or renovation projects.

In this article we’ll discuss the measurements for residential and basic ADA-compliant handrails on stairs.

Elements to Measure

The proper installation of a handrail, regardless of the type of building, requires an understanding of how to measure for length and height of the handrail. In the case of a handrail that conforms to the Americans with Disabilities Act (ADA) Guidelines, measuring the stair slope angle is also needed.

Measuring Handrail Length

The length of the sloped section of handrail is measured on a line running along the nosings of all steps, starting at the nosing of the top landing and running to the floor at the lower end. This is called the Nosing Line.

ADA compliant stair handrails, mandatory in commercial settings, must run the full length of the Nosing Line. In addition, they require a 12” horizontal section at the top, starting at a point directly above the upper nosing.

In residential settings, handrails conform to some but not all elements of the ADA Guidelines. The railing must be continuous, starting at the nosing of the upper landing and extending at a minimum to the nosing of the lowest step or “riser”. For optimal safety, whenever possible the handrail should run the entire length of the Nosing Line.

Measuring Handrail Height

The top surface of the handrail should be between 34 and 38 inches above the floor, or above the Nosing Line.

Some installation guides suggest marking the height by measuring from the nosings of the steps. Because brackets should be fastened to studs, or an equivalent solid structural member in the wall, it’s helpful to know where the Nosing Line is since the studs are unlikely to line up exactly with the steps.

Note: In areas where children will be the primary handrail users, the maximum handrail height is 28”. If there is an adult handrail present, there should be a minimum of 9” of clearance between the two handrails.

Measuring for Stair Slope

Determining the stair slope is required to create the correct transition angle between the horizontal and sloped sections of an ADA-compliant handrail. If the slope is between 30 and 34 degrees, you should be able to use a standard 32-degree bend. If not, you may require a custom combination of bends or a Promenaid Universal Bend.

In order to calculate slope, measure the rise of the steps and the tread run. You can use the table below to find the slope — also called stair pitch or angle of inclination — in degrees. The angles where a standard 32-degree bend can be used are shown in grey.


A smartphone app can also be used to measure the stair slope. Position the long edge of your smartphone along the Nosing Line or, if there is a molding running parallel to the stair slope you can measure its angle instead.

Now that you’ve learned how to measure for a stair railing, you’re ready to contact us at Promenaid to ask an expert. We’ll help you design the perfect handrail for your home, business or for your customer. Beautiful, code-compliant, easy to install and delivered in as little as 24 hours.


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