KDP Expected Cover Size vs Submitted File Size: How to Fix the Error

What KDP Means by Expected Cover Size

Expected cover size is the full cover size KDP calculated from your current book settings.

For a paperback, KDP's paperback cover guidance says the cover file should include the back cover, spine, and front cover in one PDF. The full cover width includes:

The full cover height includes:

That is why a 6 x 9 paperback does not use a 6 x 9 upload PDF. 6 x 9 is the trim size of the finished book page. The uploaded paperback cover PDF is wider because it also includes the back cover, spine, and bleed.

KDP provides an official Print Cover Calculator and Templates page for this. You can also use the KDP Cover Size Calculator to calculate full cover width, height, spine width, bleed, and layout from your current book settings.

What Submitted File Size Means

Submitted file size is the actual page size of the PDF KDP received.

It is not the size you meant to create. It is not the size written in your design file name. It is the real page size inside the exported PDF.

That matters because the export step can change things:

• a front-cover design can be exported as a single front-cover PDF;
• a converter can add margins;
• a PDF can become A4 or Letter;
• an old full cover can become too narrow after page count changes;
• a source file can be correct while the exported PDF is scaled.

Use this check before changing the design:

Why Your Trim Size Is Not the Full Cover Size

This is the most common misunderstanding.

If your book trim size is 8.5 x 11, your front cover panel is 8.5 x 11 before bleed. But your paperback cover upload is not only the front panel. It needs the back cover, spine, front cover, and bleed.

One Reddit example shows the mismatch clearly: KDP expected 17.320 x 11.250, but the submitted file was only 11.000 x 8.500. The thread does not include a final approval update, so it should not be treated as a complete repair case. But the size pair is useful: the submitted file looked like a single page or front-cover-sized file, while KDP expected a full wraparound cover.

Use this table to read the mismatch:

Why Page Count Can Change the Expected Cover Size

Spine width is part of the full cover width. KDP's cover sizing depends on page count and paper type, so a cover that fit one version of the book can stop fitting after the manuscript changes.

In one KDP page-count case, a user had previously published a book with one cover size, then saw KDP expect a slightly wider cover for a new book. The user later realized the new book had more pages. That made the spine wider, which changed the expected full cover width.

This does not mean every small width difference is caused by page count. But page count is one of the first things to check.

How to Fix the Error

Start with the numbers before changing the PDF.

1. Confirm the current KDP print settings

Open the KDP title setup and check:

• trim size;
• page count;
• paper type;
• binding or cover format;
• bleed setting.

If any of these changed after the cover was made, the expected cover size may have changed too.

2. Generate a fresh KDP template

Use KDP's Print Cover Calculator and Templates, or calculate the size with the KDP Cover Size Calculator.

Do this from the current book settings, not from memory and not from a previous book.

3. Compare the expected size with your source file

Check whether your source design is truly the full cover size.

4. Rebuild the source file when needed

If your submitted file is front-cover-sized, do not stretch it into a full cover. You need a full layout with back cover, spine, and front cover.

If your old full cover is only slightly too narrow, update the source file with the current spine width. Stretching the final PDF can distort the front cover, spine text, barcode area, and safe zones.

5. Check the exported PDF page size

After export, open the PDF properties or inspect it with a PDF tool. Confirm the PDF page size matches KDP's expected cover size.

This is where converter problems show up. A JPG-to-PDF case involved tools adding margins, scaling, A4 sizing, or unexpected zoom. The user eventually produced an exact-size PDF, but the lesson is broader: always check the final PDF page size, not only the source image.

Do Not Stretch the Old PDF

If KDP expects 17.930 x 11.250 and your submitted file is 15.433 x 11.250, it can be tempting to drag or scale the PDF wider.

That can create new problems.

Scaling a finished cover can:

• distort front and back cover art;
• move spine text out of position;
• shift the barcode area;
• make safe-area problems worse;
• blur images or text;
• hide the real source of the mismatch.

Fix the source layout instead. Use the current full cover dimensions, update the spine width, then export a new PDF.

When to Rebuild the Cover

Sometimes the cleanest fix is to rebuild from the right size.

If you want to fix the existing file, start with the KDP Cover Size Calculator. If the front cover is still usable, convert it into a full paperback file. If the cover design itself is not working, rebuilding may be faster than patching.

FAQ

Why is KDP expected cover size wider than my trim size?

Because paperback cover size is not the same as trim size. KDP expects a full cover PDF with back cover, spine, front cover, and bleed. The trim size is only the finished page size of the book.

Why does the height match but the width is wrong?

That often means the trim height and vertical bleed are right, but the full cover width is wrong. Check spine width, page count, paper type, left/right bleed, and whether you used the current KDP template.

Can page count change the expected cover size?

Yes. Page count affects spine width, and spine width is part of the full cover width. If the manuscript was revised or reformatted, regenerate the template before re-uploading the cover.

Can Canva export the wrong submitted file size?

Any design or export tool can produce the wrong final PDF size if the canvas, export settings, or converter changes the page dimensions. The important check is the exported PDF page size, not the design preview.

Should I resize the PDF or rebuild the source file?

Rebuild or update the source file when the full cover size is wrong. Resizing the final PDF can distort the artwork and move spine, barcode, or safe-area elements.

Does fixing the size guarantee KDP approval?

No. Fixing the size only addresses the size mismatch. KDP may still flag bleed, safe area, barcode, PDF structure, metadata, manuscript, or policy issues.

If the size matches but KDP still rejects the PDF cover, check the PDF cover rejection guide.