KDP Bleed, Margin & Gutter Calculator
Calculate your KDP interior page size, gutter and margins from trim size and page count.
What is the KDP Bleed, Margin & Gutter Calculator?
Getting a KDP paperback interior file rejected (or printed with text too close to the spine) almost always traces back to one of three numbers: bleed, gutter or margins. This calculator computes all three from your trim size and page count using Amazon KDP's own published formatting rules.
The rules this uses
- Bleed: if your interior has any edge-to-edge images or color, KDP requires 0.125" of bleed added to the top, bottom and outside edge of your page (not the spine edge) — so a 6"×9" trim becomes a 6.125"×9.25" document page size.
- Gutter (inside margin): increases with page count to leave room for the binding: 0.375" for 24–150 pages, 0.5" for 151–300, 0.625" for 301–500, 0.75" for 501–700, and 0.875" for 701–828 pages.
- Outside/top/bottom margins: at least 0.25" without bleed, or 0.375" with bleed.
How to use it
- Pick a common trim size or enter a custom one.
- Enter your final formatted page count.
- Check the box if your interior includes bleed elements.
- Set your document's page size, inside (gutter) margin and outside margins in your word processor or layout software to the numbers shown.
Always do a final check against Amazon KDP's own current formatting guidelines before uploading, since these specs can be revised.