Spine & margin calculator
Pick a trim size, paper and page count. Everything else follows KDP’s paperback rules.
Your book
Paper 0.002 in a page
KDP allows 24–590 pages for 8.5 × 11 in, white.
Ink
Interior bleed
- Spine width
- 0.279 in
- Inside margin (gutter)
- 0.375 in
- Full cover
- 17.529 × 11.25 in
- Page count
- Within KDP’s range
Details
- Interior page size
- 8.5 × 11 in
- Outside, top and bottom margins
- at least 0.25 in
- Spine
- 124 pp × 0.002 in
- Page limit
- 24–590 pages
- Cover bleed
- 0.125 in on every edge
- Spine text
- Allowed (80 pages or more)
KDP gutter by page count
| 24–150 pages | 0.375 in |
|---|---|
| 151–300 pages | 0.5 in |
| 301–500 pages | 0.625 in |
| 501–700 pages | 0.75 in |
| 701–828 pages | 0.875 in |
Numbers from KDP’s paperback guidelines (checked Oct 1, 2026).
Want the cover built to this size?
The studio recalculates it every time your page count changes.