Free tools
Six tools for a book on its way to KDP and the ebook stores. No account and no limits.
Before typesetting
Margin & gutter calculator
The inside (gutter), outside, top and bottom margins KDP requires for your paperback, from trim size and page count.
Spine & cover size
The spine width and full cover size for a KDP paperback, from page count, paper stock and trim size.
Structure review
See the heading tree a .docx will be typeset as: which headings it declared, which were inferred, and from what evidence.
Checking the finished files
Print PDF checker
Check an interior PDF against KDP's print requirements — page count, trim size, bleed, fonts, color space — then count widows and orphans.
Cover size checker
Check that a full-wrap cover PDF fits your interior and, if not, which mistake it is: paper stock, page count, front cover only, spine text near a fold.
EPUB accessibility checker
Check an EPUB's accessibility metadata against EPUB Accessibility 1.1 and the European Accessibility Act, and whether its claims are true of the file.