What size should my full KDP paperback cover be?

The full-wrap cover is: bleed (0.125") + back cover width + spine width + front cover width + bleed (0.125") wide, and trim height plus 0.25" of bleed tall. For an 8.5"×11" book with 100 white-paper pages that is 17.4752" × 11.25".

Why did my cover size change after editing the interior?

Spine width is page count × per-page paper thickness, and the spine sits in the middle of the full wrap. Any page-count or paper change alters the spine and therefore the total cover width, so the cover must be re-exported after interior edits.

Does bleed change the cover dimensions?

KDP covers always include 0.125" bleed on every outer edge — it is not optional like interior bleed. The dimensions this calculator outputs already include that bleed, so upload your cover PDF at exactly this size.

Where does the barcode go?

If you do not supply your own barcode, KDP prints one inside a 2" × 1.2" white box in the lower-right corner of the back cover. Keep artwork and text out of that area; a self-supplied barcode must sit at least 0.76" from the bottom edge and 0.25" from the spine.

KDP Cover Size Calculator

Get the exact full-wrap cover dimensions — back cover, spine, front cover and bleed — for any KDP trim size and page count.

Trim size

Final interior page count

Paper / ink

inches mm

Full cover width

17.4752" (443.87 mm)

Full cover height

11.25" (285.75 mm)

Spine width

0.2252" (5.72 mm)

Front / back panel

8.5" (215.9 mm) × 11" (279.4 mm)

Data source: spec version kdp-spec-2026-08, last verified against the official KDP help pages on 2026-08-25.

KDP can change its specifications at any time — always confirm against the official pages before uploading. This tool gives print-spec math only; it does not guarantee KDP acceptance. All calculations run in your browser and nothing you enter is uploaded or stored.

How the KDP cover calculator works

A KDP paperback cover is one continuous image: back cover, spine and front cover, plus mandatory 0.125" bleed on every outer edge. The formulas are:

Cover width = 0.125" + trim width + spine + trim width + 0.125"
Cover height = 0.125" + trim height + 0.125"
Spine = page count × per-page paper thickness (see the spine calculator)

This tool reuses the same versioned spine specification as the spine calculator, so a page-count change updates the spine and the full wrap together.

Worked example: 8.5" × 11", 100 pages, white paper

Spine: 100 × 0.002252" = 0.2252". Cover width: 0.125 + 8.5 + 0.2252 + 8.5 + 0.125 = 17.4752". Cover height: 11 + 0.25 = 11.25". Upload the cover PDF at exactly 17.4752" × 11.25" — KDP trims the 0.125" bleed off each edge during printing.

Common mistakes

Designing only a front cover. KDP paperbacks need the full wrap — back, spine and front in a single file at the size above.
Exporting the cover before the final page count. The spine, and therefore the total width, changes with every interior edit.
Placing artwork in the barcode area. KDP prints its barcode inside a 2" × 1.2" white box in the lower-right of the back cover, covering anything underneath.
Putting critical elements at the edges. The outer 0.125" is trimmed away; keep text and logos well inside the trim lines.

Frequently asked questions

What size should my full KDP paperback cover be?: The full-wrap cover is: bleed (0.125") + back cover width + spine width + front cover width + bleed (0.125") wide, and trim height plus 0.25" of bleed tall. For an 8.5"×11" book with 100 white-paper pages that is 17.4752" × 11.25".
Why did my cover size change after editing the interior?: Spine width is page count × per-page paper thickness, and the spine sits in the middle of the full wrap. Any page-count or paper change alters the spine and therefore the total cover width, so the cover must be re-exported after interior edits.
Does bleed change the cover dimensions?: KDP covers always include 0.125" bleed on every outer edge — it is not optional like interior bleed. The dimensions this calculator outputs already include that bleed, so upload your cover PDF at exactly this size.
Where does the barcode go?: If you do not supply your own barcode, KDP prints one inside a 2" × 1.2" white box in the lower-right corner of the back cover. Keep artwork and text out of that area; a self-supplied barcode must sit at least 0.76" from the bottom edge and 0.25" from the spine.