Amazon documents all of this, but across a dozen help pages, and the numbers that cause rejections are the ones buried deepest. This is the short version, with the actual figures. Every number here is one the PuzzleBindery export engine uses to build files that pass.
Almost everything else depends on it: the gutter steps with page count, and the spine width is page count times a per-paper multiplier. Settle the page count before you size anything else.
Gutter tiers, the interior-versus-cover bleed difference, spine width per paper stock and the page ceilings nobody mentions. I’ll send the guide and a note when Amazon changes the rules.
Free, and you can leave any time. No spam, ever.
| Paper | Spine multiplier (inches per page) | Maximum pages |
|---|---|---|
| White | 0.002252 | 828 |
| Cream | 0.0025 | 776 |
| Groundwood | 0.00235 | 812 |
| Premium colour | 0.002347 | 828 |
Spine width = page count × the multiplier. A 120-page book on white paper is
120 × 0.002252 = 0.270".
| Page count | Minimum gutter (inside margin) |
|---|---|
| 24 – 150 | 0.375" |
| 151 – 300 | 0.500" |
| 301 – 500 | 0.625" |
| 501 – 700 | 0.750" |
| 701 and up | 0.875" |
The gutter alternates sides: it sits on the left of a right-hand page and the right of a left-hand page. If your margins are symmetric, the text on half the book drifts toward the binding — and a thick book swallows it.
0.25" on the outside, top and bottom.0.375".trim width + 0.125" wide by
trim height + 0.25" tall.(trim width × 2) + spine + 0.25" by trim height + 0.25".
Bleed is all-or-nothing per file. If one page bleeds, the whole interior has to be set up for bleed — you cannot mix.
1/16" clear either side of the
text, because the trim shifts slightly between copies.0.25" in from
the bottom and side trim lines. On a cover with bleed that works out to
0.375" from the edge of your file. Measuring from the file edge instead of the
trim is the usual mistake.0.25" inside the trim line. The cut has
a tolerance and it is bigger than people expect.| Trim | Typically used for |
|---|---|
| 5" × 8" | Pocket size — small grids only |
| 5.25" × 8" | Compact paperback |
| 5.5" × 8.5" | Common digest size |
| 6" × 9" | Most popular for word search and sudoku |
| 6.14" × 9.21" | Trade paperback |
| 6.69" × 9.61" | Roomier trade size |
| 7" × 10" | Roomier grids, still compact |
| 7.44" × 9.69" | Textbook proportions |
| 7.5" × 9.25" | Workbook size |
| 8" × 10" | Kids activity books |
| 8.25" × 8.25" | Square — activity and kids |
| 8.5" × 8.5" | Large square |
| 8.5" × 11" | Large print and letter size |
Tools on this site: Spine width calculator · Puzzle book studio · Longer guide to margins and bleed · All publishing guides