Free calculator
ISBN Converter, Validator & Hyphenator
Convert ISBN-10 to ISBN-13 and back, validate check digits and hyphenate any ISBN correctly using the official International ISBN Agency ranges.
How it works
ISBN-13 check digits weight the first twelve digits alternately by 1 and 3; ISBN-10 check digits use weights 10 down to 2 modulo 11 (where 10 is written X). Only ISBNs that start with 978 have an ISBN-10 equivalent.
Hyphen positions depend on the registration group and the publisher's range, so they are looked up in the official RangeMessage file.
Frequently asked questions
Do I need a new ISBN for each format?
Yes. Paperback, hardcover, ebook and audiobook editions each need their own ISBN. A simple reprint without changes does not.
Can I convert a 979 ISBN to ISBN-10?
No. ISBN-10 only exists for the 978 prefix.