Rise, going and equal steps

The total rise is the vertical distance from one finished floor to the next. You divide it into a number of equal risers, because steps of differing heights are a serious trip hazard — people quickly learn a stair's rhythm and stumble when one step breaks it. Building codes require uniform risers for exactly this reason.

A comfortable riser is roughly 175–200 mm (about 7–7¾ inches). Because the total rise rarely divides into whole steps at exactly your target, you pick the step count that gives equal risers closest to the ideal.

The rise-and-run rules of thumb

Riser height and going are linked: taller risers pair with shallower goings and vice versa. A well-known guide is 2 × riser + going ≈ 600–650 mm, which keeps the stair comfortable for an average stride. Another common rule is riser + going ≈ 450 mm. Staying within these bands gives a stair that walks well.

Our basic stair estimator divides your total rise into equal steps and pairs them with a sensible going, then reports the riser, going, and overall run so you can check the stair fits the space.

From numbers to stringers

Once the riser and going are fixed, the total run (horizontal length) and the stringer length follow directly. Knowing these before cutting tells you whether the stair fits and how long a board each stringer needs. Always check the output against the building regulations that apply to you, as limits on riser, going, and pitch vary by jurisdiction.

Frequently asked questions