Stair Calculator
The number of steps and the real step height from a total rise.
Result
Number of steps
16
Actual step height
17.50
How it works
A staircase is sized by dividing the total floor-to-floor height by a target riser height, then rounding to a whole number of steps — since you cannot build half a step. The calculator then reports the actual riser you get, which is the total divided by that whole number. Comfortable risers land around 17–19 cm, with treads deep enough to take a foot, typically 25–30 cm. Building codes in most countries set limits on both, and on headroom, so treat the result as a starting point and check your local rules before cutting anything. Every riser must be identical. The body learns the rhythm of a staircase within two steps and then stops looking, so a single step that differs by even a centimetre is a genuine trip hazard — which is why the whole height is divided evenly rather than leaving a remainder at the top or bottom.
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Frequently asked questions
What is a comfortable step height?
Around 16–19 cm per step is comfortable for most homes.
Why are all steps equal?
Uneven steps are a trip hazard, so the total rise is divided equally across every step.
What is the two-riser-plus-tread rule?
A classic comfort check: 2 × riser + tread should land around 60–65 cm. A 17 cm riser with a 28 cm tread gives 62 cm — comfortable. It captures the fact that taller steps need shallower treads to keep a natural stride.
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