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Stairs Calc

Handrail

The graspable rail along a stair; code height 34–38 in above the nosing line.

A handrail is the graspable rail that runs alongside a stair to steady you as you climb. The IRC requires it on at least one side of any flight with four or more risers, mounted 34–38 in (864–965 mm) above the nosing line, with a graspable profile (1¼–2 in round, or an equivalent shape). Example: a 14-riser stair needs a continuous handrail the full sloped length, plus the code-required end returns. The handrail length you buy is the sloped grip run plus those extensions. Don't confuse the handrail (what your hand grips) with the guardrail, the barrier that stops a fall from an open edge.

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Related terms

Guardrail (guard) The barrier protecting an open edge; minimum 36 in high (IRC residential). Baluster (spindle) The vertical infill posts of a railing; gaps must reject a 4 in sphere. Stair width The clear walking width of the flight; IRC minimum 36 in above the handrail. Nosing The lip of the tread that overhangs the riser below; ¾–1¼ in in the IRC. Handrail extension The code-required horizontal run a handrail must extend past the top and bottom steps. Volute The spiral scroll that terminates a handrail over the bullnose step.

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Handrail Length Calculator Get the handrail length for your stairs — the sloped grip run plus the code-required top and bottom extensions — with mounting height and grip diameter checked against your building code.
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Written by the Stairs Calc editorial team. Methodology and code references: see our methodology.

Built and maintained by builders, drafters and engineers who plan stairs for a living — every code limit is transcribed from the published standard and cited to its exact section.

Last reviewed 2026-06-20 against IRC 2021/2024

Stairs Calc gives accurate geometry and checks it against published building-code limits, but results are estimates for planning. Codes are adopted and amended locally and change over time. Always confirm dimensions against your local adopted code and a licensed professional before you build.