ISBN-10 ↔ ISBN-13 Converter
Convert between ISBN-10 and ISBN-13, with the correct check digit recomputed for you.
Overview
ISBN-13 replaced ISBN-10 in 2007 by prepending a 3-digit prefix (almost always '978', occasionally '979') and recomputing the check digit with EAN-13's mod-10 formula instead of ISBN-10's mod-11 formula. Converting isn't just adding or removing 3 digits — the check digit itself changes, which is what this tool handles.
Examples
ISBN-10 to ISBN-13
0306406152
9780306406157
ISBN-13 to ISBN-10
9780306406157
0306406152
How It Works
- Choose a direction: ISBN-10 → ISBN-13 or ISBN-13 → ISBN-10.
- Enter the ISBN, with or without hyphens.
- The converted ISBN, with its correct check digit, appears instantly.
Use Cases
Updating older catalog records
Convert legacy ISBN-10 records to the ISBN-13 format modern systems and barcodes expect.
Cross-referencing editions
Look up an older edition's ISBN-10 when a newer system only lists its ISBN-13.
Tips
- Only ISBN-13s starting with '978' have an ISBN-10 equivalent — '979'-prefixed ISBN-13s were assigned after the ISBN-10 space was retired and can't be converted back.
FAQ
No. Every conversion runs locally in your browser.
ISBN-10 and ISBN-13 use different checksum formulas (mod 11 vs. mod 10), so the check digit is recalculated for the new form rather than carried over.