Check local building code
Stairs are safety-critical. Building codes can specify maximum riser height, minimum tread depth, nosing, handrails, landings and headroom. Treat this as a planning estimate only.
Example
With a total rise of 108 inches and a target riser height of 7.5 inches, the calculator rounds to a practical riser count and recalculates the actual riser height. A 14-riser layout would have risers of about 7.71 inches before checking code and site constraints.
Common mistakes
Do not confuse risers with treads. The number of treads is usually one fewer than the number of risers on a straight stair run. Also remember to account for finished floor thickness, landings, nosing and available headroom.
Limitations
This calculator does not approve a stair design. Verify the result against your local building code and have safety-critical stair work checked by a qualified professional where required.
Last reviewed: 2026-05-17