ISBN-10 to ISBN-13 Converter & Validator

Paste any ISBN — with or without hyphens — to validate it and convert between ISBN-10 and ISBN-13. Free and instant.

How it works

ISBN-13 is the ISBN as an EAN-13 barcode: prefix 978 (or 979) + the first 9 digits of the ISBN-10 + a Mod-10 check digit. ISBN-10 uses a different checksum (Mod-11), which is why its last character can be an X.

Only ISBN-13s starting with 978 can be converted back to ISBN-10. The 979 range has no ISBN-10 equivalent.

Worked example: 0-306-40615-2 → 978-0-306-40615-7

1. Take the first 9 digits of the ISBN-10: 030640615 (the old check digit "2" is discarded).
2. Add the Bookland prefix: 978030640615 — now it is 12 digits, like any EAN data.
3. Compute the EAN Mod-10 check digit over those 12 digits: it comes out as 7.
4. Result: 9780306406157. Scanners read it as a normal EAN-13 barcode.

978 vs 979: what the prefix means

978 is the original "Bookland" prefix: every ISBN-10 ever issued lives in this range, which is why the conversion is reversible. 979 was opened when 978 started running out — books in the 979 range (and sheet music under 979-0) never had an ISBN-10, so there is nothing to convert back to. If a marketplace asks for an ISBN-10 for a 979 title, the correct answer is that it does not exist: supply the ISBN-13.

FAQ

Amazon rejected my ISBN — why?

Most rejections are check digit typos. Validate the ISBN above; if it is valid but still rejected, the ISBN may not match the book's registered record.

Are ISBN and EAN the same barcode?

An ISBN-13 is an EAN-13 from the "Bookland" range (978/979), so any EAN scanner reads it.

Computed with the official ISBN Mod-11 and EAN Mod-10 formulas. This tool does not query book databases.