About StairFox

What is StairFox?

StairFox is a collection of free stair calculators built for builders, contractors, and DIYers. From stringer layout and rise & run calculations to deck stairs, concrete steps, and spiral staircases — we provide accurate, code-compliant tools that run entirely in your browser.

Built for the Job Site

Every calculator is designed with real-world construction in mind. Calculations follow IRC 2018 residential building codes, and results include practical information like lumber sizes, material quantities, and printable diagrams you can bring to the job site.

Always Free

All tools are completely free to use with no signup or premium tiers. We believe professional-grade calculators should be accessible to everyone building stairs — from first-time DIYers to seasoned contractors.

Disclaimer

StairFox calculators are intended for estimation and planning purposes. Always verify calculations against local building codes and consult a licensed professional for structural projects. Building codes vary by jurisdiction.