Text & writing
ISBN checksum and converter
Check ISBN-10/13 digits and convert compatible book number formats.
A clear answer. Here’s how.
Removes spaces/hyphens, checks ISBN-10 weighted modulo 11 or 978/979 ISBN-13 weighted modulo 10, and converts valid ISBN-10 to 978 ISBN-13. Only a 978 ISBN-13 can convert back. Checksum validity does not confirm assignment, title or publisher. Does not infer hyphenation or registration groups.
See a worked example
Worked example
A fixed demonstration, separate from the values you enter above.
- ISBN
- 978-0-306-40615-7
Example result
- Compact ISBN
- 9780306406157
- Check digit
- Passes
- Equivalent other format
- 0306406152
Checksum and 978/979 prefix checks only. Does not confirm assignment, title, publisher or hyphenation. Only 978 ISBN-13 has an ISBN-10 counterpart.