Staircase Step Calculator
Enter your floor-to-floor height and choose a riser height, and see an approximate step count, tread width and stair run based on the Blondel formula (2×riser + tread ≈ 63 cm).
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Let's design your staircase together for your projectThis is a rough illustration based on the 2×riser + tread ≈ 63 cm rule (Blondel formula); other requirements such as landings, handrail width and headroom clearance are project-specific. Source: Staircase step height and width.
How are staircase step dimensions calculated?
A comfortable, walkable staircase has a mathematical relationship between its riser (step height) and tread (step depth): 2 × riser + tread ≈ 63 cm — a rule defined by the French architect François Blondel in the 17th century and still widely used today. This tool derives the step count and tread width from the floor-to-floor height and riser value you enter, using this formula.
Residential staircases commonly use a riser of 16-18 cm, paired with a tread of roughly 27-30 cm; the tool offers three riser options within this range.
How the calculation works
First, the floor-to-floor height is divided by your target riser and rounded to find the step count; the floor-to-floor height is then divided by that step count again to get the actual riser (a slight deviation from your target). That actual riser is plugged back into the Blondel formula to find the tread width, and finally the stair's horizontal run is found as (step count − 1) × tread width.
The tool also flags whether the resulting tread width falls within the 24-32 cm comfort range; falling outside it is a sign to reconsider the floor-to-floor height or riser choice.
What this doesn't cover
This is a rough model based on the Blondel formula — landing requirements, handrail width, headroom clearance, and the staircase slope/width limits set by building regulations are all project-specific and not included here.
MEEZ Mimarlık designs your staircase as part of the building's overall circulation plan, custom to your project and meeting every safety and comfort requirement.
Contact usFrequently Asked Questions
What is the Blondel formula?
2 × riser + tread ≈ 63 cm — a rule defined by the French architect François Blondel in the 17th century, describing the relationship between riser and tread dimensions for a comfortable, walkable staircase, and still widely used today.
What riser height should a residential staircase use?
Residential staircases commonly use a riser of 16-18 cm, paired with a tread of roughly 27-30 cm; the tool offers three riser options within this range.
What tread width is considered comfortable?
24-32 cm is considered the comfort range. If the resulting tread width falls outside it, that's a sign to reconsider the floor-to-floor height or riser choice.
Does this tool also calculate the landing or handrail width?
No. This is a rough model based on the Blondel formula — landing requirements, handrail width, headroom clearance, and the staircase slope/width limits set by building regulations are project-specific and not included here.