THE NUMBERS, EXPLAINED
How to use this calculator.
Case-binding board worksheet: board width is textblock width minus spine inset plus fore-edge square; spine strip width includes two board thicknesses. Joint gap belongs in case assembly, not board dimensions.
Start with your inputs
Enter textblock width (mm), textblock height (mm), fore-edge and head-tail square (mm), board inset from textblock spine edge (mm), textblock spine thickness (mm), board thickness (mm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Textblock width (mm) | 140 |
| Textblock height (mm) | 200 |
| Fore-edge and head-tail square (mm) | 3 |
| Board inset from textblock spine edge (mm) | 2 |
| Textblock spine thickness (mm) | 20 |
| Board thickness (mm) | 2 |
A worked example
With the example inputs above, each cover board width (mm) is 141. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Each cover board width (mm) | 141 |
| Each cover board height (mm) | 206 |
| Spine strip width (mm) | 24 |
How this is calculated
Each cover board width (mm)
Subtract spine inset and add fore-edge square.
Each cover board height (mm)
Add head and tail squares.
Spine strip width (mm)
Add both cover board thicknesses to textblock spine thickness.
Symbols and units
- a
- Textblock width (mm)
- b
- Textblock height (mm)
- c
- Fore-edge and head-tail square (mm)
- d
- Board inset from textblock spine edge (mm)
- e
- Textblock spine thickness (mm)
- f
- Board 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
Case-binding board worksheet: board width is textblock width minus spine inset plus fore-edge square; spine strip width includes two board thicknesses. Joint gap belongs in case assembly, not board dimensions.
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?
Each cover board width (mm); Each cover board height (mm); Spine strip width (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: Case-binding board worksheet: board width is textblock width minus spine inset plus fore-edge square; spine strip width includes two board thicknesses. Joint gap belongs in case assembly, not board dimensions.
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.
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