Book Cover Resizer (KDP) – everything it can do:

ISBN Barcode Generator

Type your ISBN and download a print-ready EAN-13 barcode for the back cover – with an optional price add-on.

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ISBN Barcode Generator at a glance

Price
Free
Account
Not needed
Watermark
None
Privacy
Files are processed inside your browser and are never uploaded.
Works on
Windows, Mac, Linux, Android and iPhone – in any modern browser
Install
Nothing to install
Checked for typosThe ISBN check digit is verified, so a wrong digit is caught before it is printed. ISBN-10 numbers are converted to ISBN-13.
Print qualitySVG is a vector file that stays sharp at any size; the PNG is 600 DPI. Standard size is 37.3 × 25.9 mm.
Price add-onAdd the 5-digit price code booksellers use, such as 51499 for $14.99, or 90000 for no price.

How to use ISBN Barcode Generator

  1. Type your ISBN – 13 or 10 digits, with or without dashes.
  2. Add a price add-on if your printer or bookshop needs one, and choose the size.
  3. Download the SVG or PNG and place it on the back cover.

Why KDP rejects covers

Most rejected covers have one of four problems: the size is wrong (a paperback cover must include the back, the spine and the front plus 0.125″ bleed on every outside edge), the spine width does not match the page count and paper, the picture is below 300 DPI, or text sits too close to the edge and could be cut off. This tool fixes all four.

eBook cover sizes by store

StoreSize made by this toolNotes
Amazon Kindle (KDP)1600 × 2560 pxHeight to width 1.6 : 1, JPG or TIFF, RGB, under 50 MB
Apple Books1600 × 2400 pxAt least 1400 px wide
Kobo Writing Life1600 × 2400 pxJPG or PNG
Google Play Books1600 × 2560 pxAt least 640 × 1024 px
Draft2Digital1600 × 2400 pxTall rectangle
IngramSpark eBook1600 × 2560 pxJPG only, RGB
Audiobook (ACX / Audible)2400 × 2400 pxSquare

Stores update their rules from time to time – check the store’s help page if a cover is rejected. If your picture is a different shape, choose to fill (crop a little), fit it with a blurred or plain background, or stretch it. Amazon suggests a thin grey border for white or very light covers so they do not disappear on a white page – the tool switches it on for you when your cover is light.

Paperback cover size: how it is worked out

Full cover width = bleed + back cover + spine + front cover + bleed. Height = bleed + trim height + bleed. KDP uses 0.125″ (3.2 mm) bleed. The spine width depends on the number of pages and the paper:

For example, a 6 × 9 inch book with 300 pages on white paper has a spine of 0.676″ and a full cover of 12.926 × 9.25 inches – 3878 × 2775 pixels at 300 DPI. KDP allows text on the spine only when the book has more than 79 pages; the tool tells you when that applies.

Front cover only, or a full cover you already have

Have only the front? The tool builds the back and spine in a colour taken from your front cover, adds your blurb and the title and author on the spine, and keeps the barcode area (2 × 1.2 in, bottom right of the back) free. The bleed is filled by mirroring the edges of your picture, so nothing important is cut off. Already have a full wrap from a designer? Choose “A full cover” – it is resized to the exact size, and you are warned if its shape suggests a different page count.

Any picture at 300 DPI

Need interior pictures for a picture book, a print at 8 × 10 inches or an A4 poster? The third tab makes any number of pictures the exact print size at 300 DPI (or 150 or 600), with an option for KDP interior bleed (+0.125″ width, +0.25″ height). Save them as JPG, PNG or one PDF.

Hardcover and other printers

Hardcover covers wrap around the boards and use different measurements. Choose “Other size / other printer” and “Type the spine width myself”, then enter the sizes from the printer’s own cover calculator – for KDP hardcovers, from the KDP cover template.

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Frequently asked questions

Do I need a barcode for Amazon KDP?
No. KDP prints a barcode on the back cover for you. You need your own for other printers, such as IngramSpark, or for bookshops.
What is the 5-digit add-on?
It shows the price to booksellers: the first digit is the currency (5 = US dollars) and the next four are the price, so 51499 is $14.99. 90000 means no price.
Is my cover uploaded anywhere?
No. Your pictures are resized and the PDF is made on your own phone or computer. Nothing is sent to a server, so unpublished covers stay private.
Can a small picture really become 300 DPI?
The file will be 300 DPI and the exact size, but enlarging cannot add detail that is not in the original. The tool tells you how much your picture is enlarged: up to about 1.5× usually prints well; more than that may look soft. For the sharpest result, start from the largest version of your design.

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