THE NUMBERS, EXPLAINED
How to use this calculator.
A line-capacity estimate using your measured average entry length. Round total lines up once, then allocate columns and pages. Does not model alphabetic headings, keep-together rules, cross-references or typography-dependent line wrapping.
Start with your inputs
Enter index entries, measured average lines per entry, usable lines per column, columns per page. Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Index entries | 500 |
| Measured average lines per entry | 1.5 |
| Usable lines per column | 50 |
| Columns per page | 2 |
A worked example
With the example inputs above, estimated whole lines is 750. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Estimated whole lines | 750 |
| Columns required | 15 |
| Index pages | 8 |
| Used lines on last page | 50 |
How this is calculated
Estimated whole lines
Round up entries × measured average lines per entry.
Columns required
Round up lines ÷ usable lines per column.
Index pages
Round up columns required ÷ columns per page.
Used lines on last page
Total lines minus the full-page capacity of all earlier pages; zero when there are no entries.
Symbols and units
- a
- Index entries
- b
- Measured average lines per entry
- c
- Usable lines per column
- d
- Columns per page
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
A line-capacity estimate using your measured average entry length. Round total lines up once, then allocate columns and pages. Does not model alphabetic headings, keep-together rules, cross-references or typography-dependent line wrapping.
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?
Estimated whole lines; Columns required; Index pages; Used lines on last page. 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: A line-capacity estimate using your measured average entry length. Round total lines up once, then allocate columns and pages. Does not model alphabetic headings, keep-together rules, cross-references or typography-dependent line wrapping.
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: percentages 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.
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