Buchrand- und Bundsteg-Rechner

KDP inside (gutter) margins must grow with page count so text does not disappear into the binding. For a 300-page paperback, plan at least 0.75 in inside margin; thicker books need 0.875 in or more. This book margin calculator gives planning minimums — always verify against current KDP specifications before export.

What margins mean in KDP paperback layout

Print margins define the safe zone where text and images stay visible after trimming and binding. KDP distinguishes:

• Outside margin — the outer edge readers see when a book lies flat
• Inside margin (gutter) — the binding side; must be widest on thick books
• Top and bottom margins — space for headers, footers, and visual balance

Authors searching book margin calculator kdp often received a rejection for text too close to the gutter. Fix margins in your source project, not by scaling PDFs in an editor.

Gutter margin by page count (planning guide)

These are practical planning targets for fiction-style interiors. KDP publishes official tables that change — cross-check before upload:

• 24-150 pages — lower inside minimums
• 151-300 pages — increase inside margin
• 301-500 pages — plan wider gutter for binding creep
• 500+ pages — treat gutter as a layout priority, not an afterthought

Apply margins in Manusly instead of Word

Microsoft Word margins do not always survive EPUB conversion, and manual spacing breaks when you change trim size. Manusly applies trim-aware margins in Theme Builder, then exports print PDF and EPUB from one project.

Next steps: how to format a book for KDP, spine width calculator, formatting features.