KDP Cover Calculator: Spine Width and Full Wrap

Amazon KDP · US paperback and eBook · no sign-up

Paperback full wrap

Your paperback

Trim size

KDP's 16 US paperback sizes, width by height, or a custom size.

Page count

KDP accepts 24 to 776 pages for this size and paper.

Ink and paper

The paper sets how thick each page is, and so how wide the spine is.

Spine width

0.750 in

19.05 mm · 225 px

Full cover, with bleed

13.000 × 9.250 in

330.2 × 235.0 mm · 3,900 × 2,775 px at 300 DPI

Spine300 pages×0.0025 in=0.7500 in

Width0.125+6.000+0.750+6.000+0.125=13.000 in

Height0.125+9.000+0.125=9.250 in

Guides, measured from the left and top edges of the file

Back cover trim: 0.125 in · 38 px
Spine fold, back: 6.125 in · 1,838 px
Spine fold, front: 6.875 in · 2,063 px
Front cover trim: 12.875 in · 3,863 px
Top and bottom trim: 0.125 in and 9.125 in from the top · 38 and 2,738 px
Safe area for text: 0.125 in inside every trim line, which is 0.250 in from the edge of the file.
Spine text: Yes, at 300 pages. Room across the spine inside KDP's 0.0625 in clearance on each side: 0.625 in (45.0 pt).
Barcode: Keep a 2 × 1.2 in area clear at the lower right of the back cover, at least 0.25 in from the spine and the trim. Without a barcode in your file, KDP adds its own to the back cover.

Bleed, trimmed off
Trim line
Spine folds
Safe area for text
Barcode box

Drawn to scale. The flat wrap the printer sees, redrawn as you change the numbers.

What changes if

Ten more pages add 0.0250 in to the spine and to the full width; ten fewer take the same away.

At 300 pages and 6 × 9 in. Your ink and paper is in bold.
Ink and paper	Per page	Spine	Full cover	Page count
Black ink, white paper	0.002252 in	0.676 in	12.926 × 9.250 in	Within KDP's limits
Black ink, cream paper	0.0025 in	0.750 in	13.000 × 9.250 in	Within KDP's limits
Black ink, groundwood paper	0.00235 in	0.705 in	12.955 × 9.250 in	Within KDP's limits
Standard color ink, white paper	0.002252 in	0.676 in	12.926 × 9.250 in	Within KDP's limits
Premium color ink, white paper	0.002347 in	0.704 in	12.954 × 9.250 in	Within KDP's limits

Switching a published book to groundwood? KDP says a book over 350 pages on cream paper, or over 525 pages on white, needs the spine on its cover adjusted after the switch.

eBook cover

Your eBook cover

Height

KDP's ideal is 2,560 px tall. The shape follows your paperback trim, 6 × 9 in.

KDP's ideal shape

1,600 × 2,560 px

A ratio of 1.6:1, height to width

Matching your paperback front

1,707 × 2,560 px

The shape of a 6 × 9 in front, a ratio of 1.50:1. That is wider than KDP's ideal of 1.6:1.

Format: JPEG or TIFF
Ideal size: 1,600 × 2,560 px, width by height. For high-definition devices, KDP asks for an image 2,500 px tall.
Smallest: 625 × 1,000 px
Largest: 10,000 px on each side
Shape: KDP calls a height to width ratio of at least 1.6:1 ideal.
File size: Under 50 MB
Color: RGB
Spine and bleed: None. The eBook cover is the front alone.
Light covers: KDP suggests a 3 to 4 px medium gray border so a white cover does not vanish against a white page.

How KDP cover size is calculated.

A KDP paperback cover is one PDF that holds the back cover, the spine and the front cover as one image. KDP gives its size as a formula, and every input comes from your book: the trim size, the page count and the paper.

Cover widthbleed + back cover + spine + front cover + bleed

Cover heightbleed + trim height + bleed

Spine widthpage count × thickness of one page

Bleed0.125 in (3.2 mm) on the top, bottom and outside edges

A worked example: 6 × 9 in, 300 pages, cream paper

The spine is 300 × 0.0025 in = 0.750 in. The width is 0.125 + 6 + 0.750 + 6 + 0.125 = 13.000 in, and the height is 0.125 + 9 + 0.125 = 9.250 in. At 300 DPI, that is 3,900 × 2,775 px. On white paper, the same book has a 0.676 in spine and a cover 12.926 in wide.

The thickness of one page

KDP's spine width per page, by ink and paper
Ink and paper	Per page	Per page, mm	100 pages	300 pages
Black ink, white paper	0.002252 in	0.0572 mm	0.225 in	0.676 in
Black ink, cream paper	0.0025 in	0.0635 mm	0.250 in	0.750 in
Black ink, groundwood paper	0.00235 in	0.0596 mm	0.235 in	0.705 in
Standard color ink, white paper	0.002252 in	0.0572 mm	0.225 in	0.676 in
Premium color ink, white paper	0.002347 in	0.0596 mm	0.235 in	0.704 in

The groundwood rate comes from KDP's paperback submission guidelines and the other four from its paperback cover page. Groundwood is for black ink only, at every trim size. Standard color prints on the same 50 to 61 lb white paper as black ink, and KDP gives it the same rate.

Page counts

KDP counts the pages of your interior file and rounds an odd count up to an even number.
The minimum is 24 pages, or 72 for standard color. The maximum depends on trim, ink and paper, from 550 to 828 pages.
Spine text needs 80 pages or more: KDP prints it only on books with more than 79 pages.

The zones KDP asks you to respect

Bleed: Backgrounds and images run 0.125 in (3.2 mm) past the trim on the top, bottom and outside edges, so no white edge shows after trimming.
Text: At least 0.125 in (3.2 mm) inside the trim lines, and no front or back cover text runs onto the spine.
Borders: KDP advises against them. If you use one, it should sit at least 0.25 in (6.4 mm) inside the trim line.
Spine: At least 0.0625 in (1.6 mm) between spine text and each edge of the spine. The folds can land up to 0.0625 in either side of where you drew them.
Type: 7 pt or larger.
Images: 300 DPI or more at their printed size.
Barcode: 2 × 1.2 in suggested, 1.4 × 0.8 in at the smallest, at least 0.25 in from the spine and the trim. Leave the spot clear and KDP adds its own barcode to the back cover. A cover with images or text in the barcode spot is rejected.

Common KDP cover sizes.

Full cover width with bleed for five popular trims, on the three black-ink papers. Pixels are at 300 DPI.

KDP paperback full cover size, with 0.125 in bleed on every outside edge
Trim and pages	Height	White paper	Cream paper	Groundwood paper
5 × 8 in, 100 pages	8.250 in2,475 px	10.475 inspine 0.225 in · 3,143 px	10.500 inspine 0.250 in · 3,150 px	10.485 inspine 0.235 in · 3,146 px
5 × 8 in, 200 pages	8.250 in2,475 px	10.700 inspine 0.450 in · 3,210 px	10.750 inspine 0.500 in · 3,225 px	10.720 inspine 0.470 in · 3,216 px
5 × 8 in, 300 pages	8.250 in2,475 px	10.926 inspine 0.676 in · 3,278 px	11.000 inspine 0.750 in · 3,300 px	10.955 inspine 0.705 in · 3,287 px
5 × 8 in, 400 pages	8.250 in2,475 px	11.151 inspine 0.901 in · 3,345 px	11.250 inspine 1.000 in · 3,375 px	11.190 inspine 0.940 in · 3,357 px
5.5 × 8.5 in, 100 pages	8.750 in2,625 px	11.475 inspine 0.225 in · 3,443 px	11.500 inspine 0.250 in · 3,450 px	11.485 inspine 0.235 in · 3,446 px
5.5 × 8.5 in, 200 pages	8.750 in2,625 px	11.700 inspine 0.450 in · 3,510 px	11.750 inspine 0.500 in · 3,525 px	11.720 inspine 0.470 in · 3,516 px
5.5 × 8.5 in, 300 pages	8.750 in2,625 px	11.926 inspine 0.676 in · 3,578 px	12.000 inspine 0.750 in · 3,600 px	11.955 inspine 0.705 in · 3,587 px
5.5 × 8.5 in, 400 pages	8.750 in2,625 px	12.151 inspine 0.901 in · 3,645 px	12.250 inspine 1.000 in · 3,675 px	12.190 inspine 0.940 in · 3,657 px
6 × 9 in, 100 pages	9.250 in2,775 px	12.475 inspine 0.225 in · 3,743 px	12.500 inspine 0.250 in · 3,750 px	12.485 inspine 0.235 in · 3,746 px
6 × 9 in, 200 pages	9.250 in2,775 px	12.700 inspine 0.450 in · 3,810 px	12.750 inspine 0.500 in · 3,825 px	12.720 inspine 0.470 in · 3,816 px
6 × 9 in, 300 pages	9.250 in2,775 px	12.926 inspine 0.676 in · 3,878 px	13.000 inspine 0.750 in · 3,900 px	12.955 inspine 0.705 in · 3,887 px
6 × 9 in, 400 pages	9.250 in2,775 px	13.151 inspine 0.901 in · 3,945 px	13.250 inspine 1.000 in · 3,975 px	13.190 inspine 0.940 in · 3,957 px
7 × 10 in, 100 pages	10.250 in3,075 px	14.475 inspine 0.225 in · 4,343 px	14.500 inspine 0.250 in · 4,350 px	14.485 inspine 0.235 in · 4,346 px
7 × 10 in, 200 pages	10.250 in3,075 px	14.700 inspine 0.450 in · 4,410 px	14.750 inspine 0.500 in · 4,425 px	14.720 inspine 0.470 in · 4,416 px
7 × 10 in, 300 pages	10.250 in3,075 px	14.926 inspine 0.676 in · 4,478 px	15.000 inspine 0.750 in · 4,500 px	14.955 inspine 0.705 in · 4,487 px
7 × 10 in, 400 pages	10.250 in3,075 px	15.151 inspine 0.901 in · 4,545 px	15.250 inspine 1.000 in · 4,575 px	15.190 inspine 0.940 in · 4,557 px
8.5 × 11 in, 100 pages	11.250 in3,375 px	17.475 inspine 0.225 in · 5,243 px	17.500 inspine 0.250 in · 5,250 px	17.485 inspine 0.235 in · 5,246 px
8.5 × 11 in, 200 pages	11.250 in3,375 px	17.700 inspine 0.450 in · 5,310 px	17.750 inspine 0.500 in · 5,325 px	17.720 inspine 0.470 in · 5,316 px
8.5 × 11 in, 300 pages	11.250 in3,375 px	17.926 inspine 0.676 in · 5,378 px	18.000 inspine 0.750 in · 5,400 px	17.955 inspine 0.705 in · 5,387 px
8.5 × 11 in, 400 pages	11.250 in3,375 px	18.151 inspine 0.901 in · 5,445 px	18.250 inspine 1.000 in · 5,475 px	18.190 inspine 0.940 in · 5,457 px

Every width is bleed + back + spine + front + bleed, rounded to the thousandth of an inch. For any other trim, page count or paper, use the calculator above. For help picking a size, read our guide to KDP trim sizes, and for every other cover measurement, the guide to KDP book cover size.

Using these numbers in a design app.

The steps are the same in any design app that can export a PDF at 300 DPI:

Make a new document at the full cover size, bleed included. If the app asks for pixels, use the pixel size at 300 DPI.
Add vertical guides at the back trim, both spine folds and the front trim, measured from the left edge. Add horizontal guides 0.125 in from the top and the bottom.
Run the background and any edge-to-edge art all the way to the edge of the document, through the bleed.
Keep the title, author name and back cover copy inside the safe area, and the spine text inside the spine's clearance.
Leave the barcode box clear, unless you supply your own barcode.
Hide or delete the guides, then export one PDF with transparencies flattened and fonts embedded.

KDP's own cover calculator and template generator also gives you a template as a PDF and a PNG to use as a guide layer. Take it out before you export: KDP asks for no template text or guides in the file you upload.

Before you upload.

KDP's checklist for a paperback cover, in plain words:

One PDF, with the back cover, spine and front cover as one image.
Every image at 300 DPI or more at its printed size.
Transparencies flattened and fonts embedded.
No crop marks, color bars, template text or guides.
No file security. Locked or encrypted files fail review.
Title, author name, edition and ISBN on the cover matching your book's details on KDP exactly.
40 MB or less if you can manage it. KDP will not convert a cover file over 650 MB.

Then compare your file with the template from KDP's cover calculator for your trim, page count and paper. To hold it in your hands first, order a proof copy.

Hardcover and dust jackets

This calculator covers paperbacks and eBooks only. A hardcover case wrap folds around the boards and has a hinge beside the spine, so its size works differently. KDP's cover calculator makes hardcover and dust jacket templates for your trim and page count. Build to that template.

Why the spine keeps moving. And how Inkbound keeps up.

The spine comes from the page count, and the page count comes from the interior: trim, type size, line spacing and every late edit. Change one, and last week's cover file no longer fits.

One page count
Inkbound sizes the gutter and the full cover wrap from the same page count, and offers an estimate from your manuscript at your trim and type size.
KDP's numbers, built in
The Cover lab builds the back, spine and front at your trim, custom sizes included, with 0.125 in of bleed and KDP's spine rate for white, cream or groundwood paper, or standard or premium color.
The gap, flagged
If the book grows or shrinks, Publish flags the gap so you can update the count before you export. A small change refits the painted spine, and a big one asks you to repaint.

Opens November 21 See the Cover lab

Inkbound is a Mac app for Apple Silicon Macs with macOS 12 or later: $1 for the first week, then $14.99/month, or $129 once for Lifetime.

Cover size questions.

Is this the same as KDP's cover calculator?

No. It is our own calculator, built on the formula and page thicknesses KDP publishes on its help pages. KDP's cover calculator also gives you a template to download as a PDF or PNG, and it covers hardcover. Check your final file against KDP's template before you upload.

How do I calculate KDP spine width?

Multiply the page count by the thickness of one page: 0.002252 in for white paper, 0.0025 in for cream, 0.00235 in for groundwood, 0.002252 in for standard color and 0.002347 in for premium color. A 300-page book on cream paper has a 0.750 in spine.

What size is a KDP cover for a 6 × 9 book?

It depends on the page count and paper, because the spine sits between the back and front panels. The height is always 9.25 in: the 9 in trim plus 0.125 in of bleed at the top and bottom. A 300-page 6 × 9 book on cream paper has a 0.750 in spine and a full cover of 13.000 × 9.250 in, or 3,900 × 2,775 px at 300 DPI. On white paper, the same book is 12.926 × 9.250 in.

How many pages do I need for spine text?

80 or more. KDP's help says it prints spine text only on books with more than 79 pages, and its Cover Creator tool needs 80. Keep at least 0.0625 in between the text and each edge of the spine.

Does groundwood paper change the spine?

Yes. Groundwood is 0.00235 in per page, thicker than white paper and thinner than cream, so a 300-page book gets a 0.705 in spine. KDP offers it with black ink only. If you switch a published book to groundwood, KDP says a book over 350 pages on cream or 525 pages on white needs the spine on its cover adjusted.

What size is a KDP eBook cover?

KDP's ideal is 1,600 × 2,560 px (width × height), a ratio of 1.6:1, saved as a JPEG or TIFF under 50 MB in RGB. The smallest it takes is 625 × 1,000 px, and the largest is 10,000 px on each side.

Does an eBook cover need bleed?

No. An eBook cover is the front alone, a screen image with no spine, back cover or bleed. Bleed is for the printed paperback wrap, which needs 0.125 in past every outside edge.

What if my page count changes after I make the cover?

The spine changes, so the full cover width changes with it. On cream paper, every 10 pages add 0.025 in. Work out the new size, move the spine and the panels beside it, and upload the new cover with the new interior. In Inkbound, Publish flags the gap when the page count moves, and the Cover lab refits a painted spine after a small change or asks you to repaint after a big one.

Checked against KDP help on October 22, 2026

Every number on this page comes from KDP's own help pages: Create a Paperback Cover, Paperback Submission Guidelines, Print Options, Barcodes, Groundwood Paper and eBook cover image criteria. KDP can change them, so check your file against KDP's cover calculator before you upload.

Every KDP cover measurement Choosing a KDP trim size Royalty and print cost Inkbound's Cover lab Book formatting on Mac

KDP cover calculator. Spine, full wrap and eBook sizes.