THE NUMBERS, EXPLAINED
How to use this calculator.
Subtract unusable ends before dividing by full label pitch. Label pitch includes any inter-label gap. Partial labels are not counted.
Start with your inputs
Enter roll length (m), label pitch including gap (mm), unusable leader (mm), unusable trailer (mm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Roll length (m) | 30 |
| Label pitch including gap (mm) | 100 |
| Unusable leader (mm) | 200 |
| Unusable trailer (mm) | 300 |
A worked example
With the example inputs above, usable labels is 295. Change the inputs to explore your own scenario.
Putting the example numbers into the formula
Usable labels
floor(((30) × 1000-(200)-(300)) ÷ (100)) = 295
Usable roll (mm)
(30) × 1000-(200)-(300) = 29,500
Tail after full labels (mm)
((30) × 1000-(200)-(300)) rem (100) = 0
| Result | Example answer |
|---|---|
| Usable labels | 295 |
| Usable roll (mm) | 29,500 |
| Tail after full labels (mm) | 0 |
How this is calculated
Usable labels
floor((a × 1000-c-d) ÷ b)
Usable roll (mm)
a × 1000-c-d
Tail after full labels (mm)
(a × 1000-c-d) rem b
Symbols and units
- a
- Roll length (m)
- b
- Label pitch including gap (mm)
- c
- Unusable leader (mm)
- d
- Unusable trailer (mm)
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
floor(x) rounds down towards negative infinity.
rem means the remainder after division; it is not a percentage sign.
Assumptions and limits
Subtract unusable ends before dividing by full label pitch. Label pitch includes any inter-label gap. Partial labels are not counted.
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?
Usable labels; Usable roll (mm); Tail after full labels (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: Subtract unusable ends before dividing by full label pitch. Label pitch includes any inter-label gap. Partial labels are not counted.
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: algebra and proportional reasoning ↗
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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