EAN and ISBN check digit calculator and validator (GTIN)
Use this EAN check digit calculator: paste one or more numbers – one per line, spaces and hyphens are fine. The tool detects the type from the length, verifies the check digit according to GS1 or the ISBN standard and converts ISBNs.
Source: GS1 General Specifications – 7.9 Check digit calculation; GS1 Prefixes. Updated: .
How it is calculated
Barcode numbers on products (EAN/GTIN/UPC) and book numbers (ISBN) end with a check digit. It is calculated from the other digits and catches typos: every single wrong digit and most swaps of adjacent digits. A correct check digit only means the number is well-formed – not that the product or book exists.
How to check an EAN
- Under “What do you want to do?” choose to validate a number or calculate the check digit.
- Paste one or more numbers, one per line – spaces and hyphens are fine.
- Read type (EAN-8, EAN-13, UPC-A, GTIN-14, ISBN), check digit and, for ISBNs, the conversion in the results.
How many digits does each number have?
- EAN-8 – 8 digits, for small packages
- UPC-A / GTIN-12 – 12 digits, mainly USA and Canada; with a leading 0 it equals an EAN-13
- EAN-13 / GTIN-13 – 13 digits, the standard retail barcode outside North America
- GTIN-14 – 14 digits, for cases and trade units (first digit = packaging indicator)
- ISBN-13 – 13 digits starting with 978 or 979 (since 2007); ISBN-10 – the older 10-digit form
How the check digit is calculated
GS1 method (EAN, UPC, GTIN, ISBN-13): Starting from the right, multiply the digits alternately by 3 and 1 and add them up. The check digit tops the sum up to the next multiple of 10. Example 400638133393: 4·1 + 0·3 + 0·1 + 6·3 + 3·1 + 8·3 + 1·1 + 3·3 + 3·1 + 3·3 + 9·1 + 3·3 = 89 → check digit 1, giving 4006381333931.
ISBN-10 (modulus 11): The nine digits are weighted 10, 9, 8 … 2. The check digit tops the sum up to a multiple of 11; if it comes out as 10, an X is written. Example 0-306-40615-? → sum 130 → 11 − (130 mod 11) = 2.
ISBN-10 → ISBN-13: add 978 in front, drop the old check digit and recalculate it with the GS1 method (0-306-40615-2 → 978-0-306-40615-7). ISBNs starting with 979 have no 10-digit equivalent.
Does the prefix tell the country of origin?
No. The first digits (GS1 prefix) only show which national GS1 organisation issued the number to a company. A company may obtain its numbers from GS1 in another country, and the product can be made anywhere. That is why the tool only shows “Prefix xyz” and names just the fixed special ranges: 977 (periodicals), 978/979 (books, 979-0 printed music) and 020–029, 040–049 and 200–299 for retailers’ and companies’ internal numbers.
Your numbers are processed only in your browser and are not sent anywhere.
More check digit tools: the Luhn algorithm checker, the IBAN checker and, for product labels, the QR code generator.
Frequently asked questions
How do I calculate an EAN check digit?
Choose “Calculate the check digit” above and enter the first 12 digits of an EAN-13 (or 7 of an EAN-8, 11 of a UPC-A). By hand: from the right, multiply alternately by 3 and 1, add everything and top up to the next multiple of ten.
Does a valid check digit mean the barcode is registered?
Not necessarily. The check digit only checks the structure. Whether a number is actually assigned to a product is known only to its owner or GS1’s registry (e.g. “Verified by GS1”).
Does prefix 690–699 mean “made in China”?
No. GS1 prefixes show which GS1 member organisation issued the number, not where the product was made. GS1 states explicitly that the prefix does not indicate the country of origin.
What does the X in an ISBN-10 mean?
X stands for the check value 10: the modulus-11 method can produce a two-digit result, but there is only room for one character. ISBN-13 never uses an X.
Can every ISBN-13 be converted to an ISBN-10?
Only ISBN-13s starting with 978. The 979 prefix was introduced with the 13-digit ISBN, so these ISBNs have no 10-digit form.
Sources and legal basis
- GS1 General Specifications – 7.9 Check digit calculation; GS1 Prefixes
- GS1 – Check Digit Calculator
- GS1 – GS1 Company Prefix (prefix ≠ country of origin)
- International ISBN Agency – ISBN Users’ Manual
- ISO 2108: ISO 2108:2017 – International standard book number (ISBN)
As of: · Editorial policy
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