Formula
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations use standard floating-point arithmetic; exact integer and fraction tools identify their own precision rules.
- Ideal uniformly rotating stair; does not assess tread inner width, headroom, guards or code compliance.
Example Calculation
- Total rise: 3000 mm
- Risers: 15
- Total rotation: 360 °
- Walk-line radius: 800 mm
Total rise = 3000 mm; Risers = 15; Total rotation = 360 °; Walk-line radius = 800 mm. Primary result: 200.
Frequently asked questions
How do I use this calculator?
Enter total rise, risers, total rotation, walk-line radius. The result updates automatically. Use Reset to restore the example values.
What method does it use?
rise per step=height/n; rotation=total angle/n; arc going=radius ×rotation radians.. Ideal uniformly rotating stair; does not assess tread inner width, headroom, guards or code compliance.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.