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Stair Calculator

stair-calculator

Calculate risers, tread depth, stair angle and stringer length from floor height and available run.

🛡 Privacy-first⚡ Fast🔓 No signup📱 Mobile friendly

Floor height (cm)Available run (cm)Target riser (cm)

Stair width (cm) — quantity aid

Dynamic diagram

⚠️ Results are estimates for takeoff and planning. Do not use them as a substitute for structural design, specifications or local building codes; consult a qualified professional when required.

💡 Useful information

Calculate stair dimensions from floor height, available horizontal run and target riser height, with a dynamic side diagram.

Runs directly in a modern browser.
Works on phones and desktop computers.
Reuse it without creating an account.

ℹ️ How to use

Enter your data or choose the required file.
Adjust the available options.
Run the tool and review the result.
Copy or download the result when needed.

❔ Frequently asked questions

Does it check building-code compliance?

It provides general geometric indicators only; riser, tread and guard requirements vary by local code.

How are risers determined?

Floor height is divided by the target riser height, rounded, then the actual equal riser height is recalculated.