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KDP bleed, margin and spine calculator

Pick your trim size and page count. Get the exact PDF size, safe margins and cover dimensions KDP expects, so the Print Previewer passes first time.

Bleed: art runs to here Trim: where the page is cut Safe zone: keep text here
Does any art or background touch the page edge?
Pick the matching option in KDP's Print Options too. A mismatch is the #1 cause of margin errors.
Build your book in Layout Lab Max

Fix "This image is outside the margins"

  1. Check the page size first. With bleed, every interior page must be trim width + 0.125" by trim height + 0.25". Not trim + 0.25" on both sides.
  2. Match KDP's setting. Choose "Bleed" in Print Options if your PDF has bleed, "No Bleed" if it doesn't.
  3. Bleed goes on three edges only. Top, bottom and the outside edge. The gutter edge gets none.
  4. Run backgrounds to the very edge. A white strip near the fold or edge makes art look like it's sitting inside the margin.
  5. Keep text inside the safe zone and away from the gutter by the distance shown above.
  6. Spreads need the right pages. Left half on an even page, right half on an odd page.

Common questions

What PDF size does KDP want with bleed?

Trim width + 0.125" and trim height + 0.25". For an 8.5 × 8.5 book that's 8.625 × 8.75". Bleed is added top, bottom and outside only.

How big is the gutter margin?

0.375" up to 150 pages, 0.5" for 151-300, 0.625" for 301-500, 0.75" for 501-700 and 0.875" above that, measured from the trim edge. Outside, top and bottom: at least 0.25".

How is spine width calculated?

Page count × paper thickness: 0.002252" per page for white paper and standard colour, 0.0025" for cream, 0.002347" for premium colour.

Can art cross the fold in a double-page spread?

Yes, but there is no bleed across the gutter. Split the art into two pages that meet exactly at the trim edge, left half on an even page.