THE NUMBERS, EXPLAINED
How to use this calculator.
Uses a stadium cross-section: a rectangle plus two semicircular ends. Width must be at least height. The supplied tested flow limit alone does not account for acceleration, cooling or machine limits.
Start with your inputs
Enter line width (mm), layer height (mm), tested volumetric limit (mm³/s). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Line width (mm) | 0.45 |
| Layer height (mm) | 0.2 |
| Tested volumetric limit (mm³/s) | 8 |
A worked example
With the example inputs above, maximum model speed (mm/s) is 98.260873. Change the inputs to explore your own scenario.
Putting the example numbers into the formula
Maximum model speed (mm/s)
(8) ÷ (((0.45)-(0.2)) × (0.2)+π × ((0.2) ÷ 2)^2) = 98.260873
Extrusion cross-section (mm²)
((0.45)-(0.2)) × (0.2)+π × ((0.2) ÷ 2)^2 = 0.081416
| Result | Example answer |
|---|---|
| Maximum model speed (mm/s) | 98.260873 |
| Extrusion cross-section (mm²) | 0.081416 |
How this is calculated
Maximum model speed (mm/s)
c ÷ ((a-b) × b+π × (b ÷ 2)^2)
Extrusion cross-section (mm²)
(a-b) × b+π × (b ÷ 2)^2
Symbols and units
- a
- Line width (mm)
- b
- Layer height (mm)
- c
- Tested volumetric limit (mm³/s)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Calculation steps and notation
π is the circle constant, approximately 3.141592653589793.
Assumptions and limits
Uses a stadium cross-section: a rectangle plus two semicircular ends. Width must be at least height. The supplied tested flow limit alone does not account for acceleration, cooling or machine limits.
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?
Maximum model speed (mm/s); Extrusion cross-section (mm²). 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: Uses a stadium cross-section: a rectangle plus two semicircular ends. Width must be at least height. The supplied tested flow limit alone does not account for acceleration, cooling or machine limits.
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
Prusa: maximum volumetric speed ↗
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.
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