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The EAN-13 check digit is calculated from the preceding 12 digits using alternating weights. This calculator is useful for a quick data-entry check when a product code has been typed into a spreadsheet, catalogue, label design, or stock record.
A correct checksum identifies arithmetic consistency, not product identity. It does not confirm that a number was assigned by GS1 or that the data belongs to a specific manufacturer. Keep the original source record when correcting a value.
How to use this tool
- Enter the first 12 digits to calculate the check digit, or enter all 13 to verify it.
- Review the calculated result alongside the supplied number.
- Correct the source record before producing labels if the digits do not match.
Practical guidance
The EAN-13 check digit is a weighted checksum used to catch many data-entry mistakes. It is particularly useful when copying a code into inventory software, reconciling a product spreadsheet, or reviewing artwork before it is sent to print. Compare the result to the original source instead of quietly changing an identifier to make the arithmetic pass.
Checks before you use the output
A transposed digit can still create a different valid number, so checksum validation is only one quality check. Preserve leading zeroes when moving codes through spreadsheets, which may otherwise convert long digit strings into numbers. If the supplied final digit does not match, investigate the source data and confirm the officially assigned code.
Questions and answers
Can the tool identify the product?
No. It checks the arithmetic only; product lookup requires an independent catalogue or database.
What should I do if the check digit differs?
Check for transposed or mistyped digits and compare against the authoritative product record.
If the checksum passes, is the product code authentic?
No. The check digit only tests arithmetic consistency. It does not verify ownership, allocation, product identity, or whether a code belongs to the item being labelled.