Stair dimensions

Enter your stair measurements below

IRC R311.7

Step geometry

Stair type

Riser height (inches) — vertical height of one step

Tread depth (inches) — horizontal depth of one step

Number of risers — total steps in the flight

Clearances & width

Headroom clearance (inches) — vertical from nosing to ceiling

Stair width (inches) — clear width between walls/rails

Handrail

Handrail height (inches) — measured vertically from nosing

Handrail present?

Visual reference

Stair geometry diagram

Code check results

IRC 2021 — Section R311.7 & R311.8

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IRC quick reference

Measurement	IRC 2021 limit
Max riser height	7¾"
Min tread depth	10"
Riser consistency (max variation)	⅜" between largest & smallest
Min headroom	6'–8" (80")
Min stair width	36"
Handrail height range	34"–38"
Handrail required when	4+ risers

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