THE NUMBERS, EXPLAINED
How to use this calculator.
Miniature model only. Equal treads over full run; riser panels fit below tread thickness. This does not size human-use stairs.
Start with your inputs
Enter total miniature stair rise (mm), total miniature stair run (mm), equal steps (count), tread material thickness (mm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Total miniature stair rise (mm) | 30 |
| Total miniature stair run (mm) | 60 |
| Equal steps (count) | 6 |
| Tread material thickness (mm) | 1 |
A worked example
With the example inputs above, tread depth (mm) is 10. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Tread depth (mm) | 10 |
| Finished rise per step (mm) | 5 |
| Riser panel height below tread (mm) | 4 |
How this is calculated
Tread depth (mm)
Divide total run equally among steps.
Finished rise per step (mm)
Divide total rise by steps.
Riser panel height below tread (mm)
Subtract tread thickness from finished rise.
Symbols and units
- a
- Total miniature stair rise (mm)
- b
- Total miniature stair run (mm)
- c
- Equal steps (count)
- d
- Tread material thickness (mm)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
Miniature model only. Equal treads over full run; riser panels fit below tread thickness. This does not size human-use stairs.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Tread depth (mm); Finished rise per step (mm); Riser panel height below tread (mm). The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: Miniature model only. Equal treads over full run; riser panels fit below tread thickness. This does not size human-use stairs.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
OpenStax Prealgebra 2e — arithmetic and proportions ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
Read the quality report →