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Stair Calculator
Number of steps, riser height and tread depth.
15
Number of risers
18.33 cm
Riser height
26.33 cm
Tread depth
368.7 cm
Total run (n − 1 treads)
34.8°
Stair angle
Runs entirely in your browser. Nothing is sent anywhere.
How it works
- 1Enter your values.
- 2See the result update instantly as you type.
- 3Change any value to compare scenarios.
About this tool
Stair Calculator: Number of steps, riser height and tread depth. Type your numbers and the result is calculated instantly — no button to press, nothing to install. All math runs locally in your browser, so the values you enter are never sent anywhere.
Example
| Input | |
|---|---|
| Floor-to-floor height (cm) | 275 |
| Target riser height (cm) | 18 |
| Step length rule 2R + T (cm) | 63 |
| Result | |
| Number of risers | 15 |
| Riser height | 18.33 cm |
| Tread depth | 26.33 cm |
| Total run (n − 1 treads) | 368.7 cm |
| Stair angle | 34.8° |
How do I use the Stair Calculator?
Enter your values. See the result update instantly as you type. Change any value to compare scenarios.
Is the Stair Calculator free?
Yes. It is completely free with no sign-up, no usage limits and no watermark.
Is my data sent to a server?
No. Everything is calculated locally in your browser. Nothing you enter is uploaded, logged or stored.
Does it work on my phone?
Yes. It works in any modern browser on Android, iPhone, iPad, Windows, Mac and Linux — no app needed.