Stair geometry

Stair geometry: use total vertical rise, maximum desired riser height, tread going. Review the formula, worked example and calculation steps.

Inputs

Use the units shown

Check material properties, site conditions and applicable standards before using this estimate for design, procurement or safety decisions.

RESULT
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Formula & explanation
Risers = ceil(total rise/max riser); actual riser = total rise/risers; run = (risers−1)×going

Variables & units

Total vertical rise
m · minimum 0.001, maximum 1000000000000
Maximum desired riser height
m · minimum 0.001, maximum 1000000000000
Tread going
m · minimum 0.001, maximum 1000000000000

Worked example

2.8 m total rise, maximum 0.18 m riser and 0.28 m going gives 16 risers, 0.175 m each, and 4.2 m run.

Assumptions

Simple single flight ending at a landing. Not a code-compliance check; headroom, width, nosing, handrails and landings are excluded.

Formula version 1.0.0. JavaScript floating-point arithmetic applies. Results display up to 6 decimal places; stored values retain available precision. Use the units shown.

Practice with an example

Use the default input values to find the answer. The reset icon restores those values.

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