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.
- One straight flight ending at an upper landing; no intermediate landing or nosing adjustment. Does not certify stair-code compliance.
Example Calculation
- Total floor-to-floor rise: 2800 mm
- Maximum target rise: 180 mm
- Tread going: 260 mm
2800 mm total with target 180 mm gives 16 rises of 175 mm and 15 treads.
Frequently asked questions
How do I use this calculator?
Enter total floor-to-floor rise, maximum target rise, tread going. The result updates automatically. Use Reset to restore the example values.
What method does it use?
risers=ceil(total rise/target); actual rise=total/risers; treads=risers−1.. One straight flight ending at an upper landing; no intermediate landing or nosing adjustment. Does not certify stair-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.