Low-content book interiors: page size, margins and spine width for a 120-page book
A logbook, journal or planner interior is a PDF with the exact trim size, enough margin on the spine side, and an even page count. This page puts the numbers for a 120-page interior in one place, with the math shown.
Where the figures come from: the margin minimums and the per-page spine factors below are the figures commonly published for print-on-demand paperbacks in 2026. They were not confirmed on the printer's own help page for this article: check the current figures in your publishing platform's help pages before you upload.
Table 1: page size in the PDF
| Trim size | Width | Height | Width in points | Height in points |
|---|---|---|---|---|
| 6 x 9 in | 6 in | 9 in | 432 | 648 |
| 8.5 x 11 in | 8.5 in | 11 in | 612 | 792 |
With no bleed, the PDF page is the trim size exactly: 6 x 72 = 432 and 9 x 72 = 648; 8.5 x 72 = 612 and 11 x 72 = 792.
Table 2: minimum inside margin by page count (no bleed)
| Pages | Inside (spine side) margin |
|---|---|
| 24 to 150 | 0.375 in |
| 151 to 300 | 0.5 in |
| 301 to 500 | 0.625 in |
| 501 to 700 | 0.75 in |
| 701 to 828 | 0.875 in |
Odd pages are right-hand pages, so their inside margin is on the left; on even pages it is on the right. A 120-page interior needs at least 0.375 in on the spine side. Leaving 0.5 in gives room for lines that would otherwise run into the fold.
Table 3: spine width for 120 pages
| Paper | Inches per page | 120 pages |
|---|---|---|
| White | 0.002252 | 0.27 in |
| Cream | 0.0025 | 0.30 in |
120 x 0.002252 = 0.270 and 120 x 0.0025 = 0.300. The cover is a separate file: with a 0.125 in
bleed on each outer edge, a 6 x 9 cover on white paper is 0.125 + 6 + 0.27 + 6 + 0.125 = 12.52 in wide and 9.25 in tall,
and an 8.5 x 11 cover is 0.125 + 8.5 + 0.27 + 8.5 + 0.125 = 17.52 in wide and 11.25 in tall.
A checklist before you upload an interior
- Every page has the same size, and it matches the trim you pick (Table 1).
- The page count is even and inside the range of your margin row (Table 2).
- Nothing is printed closer to the edge than the minimums.
- The cover is built for the same page count and paper (Table 3).
- Read every page in the platform's previewer before you publish.
Want interiors that already follow these numbers? The Low-Content Interiors Pack is a 15 USD download on Gumroad: 53 designs (logs, journals, planners and paper styles) in 6 x 9 and 8.5 x 11, 106 PDFs of 120 pages each, with a 0.5 in inside margin and a licence to use them inside books you publish. A script checked the page size and page count of every file; none was uploaded to a print platform or printed. It is our own product: we sell it and earn money from each purchase, so this is a commercial link and not a neutral recommendation.