# Stair Calculator

> Determine the riser height, number of steps, and total run for a stair stringer.

Page: https://askcalculators.com/calculator/stair-calculator/
Definition: https://askcalculators.com/calculator/stair-calculator/definition.json
JSON Schema: https://askcalculators.com/calculator/stair-calculator/schema.json
Version: 7.0.0
Maintained by: AskCalculators (software project; not a credentialed reviewer)
Qualified review: pending. Automated checks do not establish professional approval.
Page status: Live
Review status: Pending

## Use
Open the calculator page and enter values. Query-string parameters can restore and bookmark a calculation.
Example: https://askcalculators.com/calculator/stair-calculator/?totalRise=108&targetRise=7

## Inputs
- totalRise: Total Rise (Floor to Floor, inches); type=number; optional; default=108
- targetRise: Target Riser Height (e.g., 7 inches); type=number; optional; default=7

## Outputs
- result: Result; format=text; primary

## Formula
Riser count = rounded total rise ÷ target riser height; actual riser = total rise ÷ riser count; tread/run values follow the selected stair geometry.

## Rules
- Empty optional inputs are undefined, not zero.
- Hidden conditional inputs are ignored.
- Do not invent missing required inputs.