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.
Want the "why" behind this tool? Read The One KDP Margin That Changes Depending on How Long Your Book Is.