ISBN barcode generator

Every ISBN-13 ends in a check digit. Multiply the first twelve digits alternately by 1 and 3, add them up, and the check digit is whatever brings the total to the next multiple of ten. A single mistyped digit always fails that test, which is why this page will not draw a barcode until the number checks out. An older ten-digit ISBN uses a different check (weights 10 down to 1, modulo 11, where X stands for 10). To convert one, put 978 in front of its first nine digits and work out a new ISBN-13 check digit.

The barcode itself is an EAN-13 symbol, often called a Bookland EAN when it carries an ISBN. The bars encode all thirteen digits, the digits are printed underneath, and the ISBN with its hyphens is printed above. The hyphens show where the group, publisher and title parts of the number split, and those split points depend on the agency’s range tables, so type the ISBN with the hyphens your agency gave you and the page keeps them. The optional five-digit add-on to the right carries a price: a 5 at the front means US dollars, so 52499 is $24.99, and 90000 means no price.

The download is drawn at 100% size, 0.33 mm per bar module, in pure black on white. The SVG is vector, which is what KDP prefers; the PNG is 1,200 dots per inch, well above KDP’s 300 PPI minimum. KDP asks that a barcode you supply is 100% black (not a four-colour black), sits on a solid white box, is at least 1.4 × 0.8 in, and stays at least 0.25 in from the spine and the trim. If you would rather not place one, leave the area clear: KDP adds a barcode to the back cover at no charge.

Where the ISBN comes from matters more than the barcode. In the United States, ISBNs are sold by Bowker through myidentifiers.com. Most other countries have one national agency, and some, like Canada, give ISBNs free; the International ISBN Agency lists them all. KDP offers a free ISBN for paperbacks and hardcovers, but its help page is plain that a free KDP ISBN can only be used on KDP and shows “Independently published” as the imprint. Each format needs its own number: the paperback and the hardcover get different ISBNs, and an ebook does not need one on KDP. The spine width calculator gives the cover size the barcode sits on.