Handrail Length

This calculator uses the Pythagorean theorem to find the sloped handrail length from a stair flight's total run and rise, then adds a separate horizontal landing rail extension. At this calculator's default dimensions, Total run (in) has a somewhat larger effect on Sloped than Total rise (in) does -- with a longer run than rise in a typical stairway, a given percentage change in run shifts the hypotenuse by more than the same percentage change in rise, though both inputs genuinely move the result since Sloped is the square root of the sum of their squares. Landing rail (in), by contrast, has no effect whatsoever on Sloped -- it is added separately, only after the sloped length is calculated, to produce the Total figure.

This distinction matters when ordering material: Sloped tells you how much rail to cut at an angle to follow the stair pitch, while Total tells you the full length to purchase including any straight horizontal run at a landing. This is a straight-line geometric estimate -- it doesn't account for rail fittings, wall-mounted bracket spacing, or code-required rail height and graspability requirements, which vary by jurisdiction.