# Stair Calculator

> Stair calculator: convert total rise into riser height, tread depth, stringer length, and step count that meet building code. Free, no signup, runs locally.

- **Canonical URL:** https://boringtoolskit.com/stair-calculator/
- **Category:** Construction & Measurement
- **Evidence level:** authored-methodology
- **Reviewed:** July 2026
- **Last verified:** 2026-10-12
- **Privacy:** Inputs and results stay in this browser unless the page clearly labels an external request.

## How it works

Risers = ceiling(total rise ÷ target riser); actual riser = total rise ÷ risers; treads = risers − 1; stringer slope = √(rise² + run²).

## Assumptions

- The stair is a straight flight with equal risers.
- The target is used to choose a count; local code controls maximum riser and minimum tread.
- Structural sizing, nosing, landings, headroom, guards, and handrails are excluded.

## Common questions

### Do I need to create an account or sign up to use the stair calculator?

No. The stair calculator is entirely no-signup and runs directly in your browser — nothing is saved or uploaded.

### Is my data safe when using the stair calculator?

Yes. All calculations happen locally on your device in the browser. No personal data or input values are stored, transmitted, or collected.

### What measurements does the stair calculator use to generate stair dimensions?

The stair calculator uses your total rise (floor-to-floor height), desired tread depth, and riser height to compute step count, run length, and stringer angles for safe, code-compliant stairs.

## Related tools

- /decking-calculator/
- /board-foot-calculator/
- /square-feet-to-linear-feet/

## Sources

- [Residential code information](https://www.iccsafe.org/products-and-services/i-codes/2024-i-codes/irc/)
- [Stairways and ladders guidance](https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.1052)

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