THE NUMBERS, EXPLAINED
How to use this calculator.
Flat jacket geometry with two equal cover panels and separately specified flap widths. Fold positions are measured from the left file edge, including bleed. Additional hinge gaps, board thickness and turn-ins are not inferred; confirm the final printer template.
Start with your inputs
Enter cover panel width (mm), cover height (mm), spine width (mm), left flap width (mm), right flap width (mm), outer bleed (mm). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Cover panel width (mm) | 150 |
| Cover height (mm) | 210 |
| Spine width (mm) | 12 |
| Left flap width (mm) | 80 |
| Right flap width (mm) | 80 |
| Outer bleed (mm) | 3 |
A worked example
With the example inputs above, flat jacket width (mm) is 478. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Flat jacket width (mm) | 478 |
| Flat jacket height (mm) | 216 |
| Fold positions from left (mm) | 83, 233, 245, 395 |
How this is calculated
Flat jacket width (mm)
Two cover widths + spine + both flaps + two outer bleeds.
Flat jacket height (mm)
Cover height + two outer bleeds.
Fold positions from left (mm)
Starting after left bleed, accumulate left flap, back cover, spine and front cover; each boundary is a fold.
Symbols and units
- a
- Cover panel width (mm)
- b
- Cover height (mm)
- c
- Spine width (mm)
- d
- Left flap width (mm)
- e
- Right flap width (mm)
- f
- Outer bleed (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
Flat jacket geometry with two equal cover panels and separately specified flap widths. Fold positions are measured from the left file edge, including bleed. Additional hinge gaps, board thickness and turn-ins are not inferred; confirm the final printer template.
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?
Flat jacket width (mm); Flat jacket height (mm); Fold positions from left (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: Flat jacket geometry with two equal cover panels and separately specified flap widths. Fold positions are measured from the left file edge, including bleed. Additional hinge gaps, board thickness and turn-ins are not inferred; confirm the final printer template.
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
IngramSpark: use printer-specific cover templates ↗
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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