EAN Barcode Check Digit Calculator
Verify or calculate the check digit of EAN-13, EAN-8, UPC-A, GTIN-14 and SSCC barcode numbers, one at a time or in bulk.
Spaces and hyphens are ignored. Accepted lengths: 8 (EAN-8), 12 (UPC-A), 13 (EAN-13 / ISBN-13), 14 (GTIN-14) and 18 (SSCC).
- Format
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- Check digit
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- Weighted sum
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How the check digit is calculated
| Position | Digit | Weight | Product |
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Bulk check — one barcode per line
| Barcode | Format | Check digit | Result |
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How it works
Every EAN, UPC and GTIN barcode number ends in a check digit that protects the rest of the number against scanning and typing mistakes. This tool applies the standard GS1 modulo-10 algorithm: starting from the digit just left of the check digit, each digit is multiplied by 3 and 1 alternately, the products are added up, and the check digit is whatever value brings that total to the next multiple of ten. It works for EAN-8, UPC-A (GTIN-12), EAN-13 and ISBN-13, GTIN-14 / ITF-14 and 18-digit SSCC logistics labels.
Switch to Calculate the missing check digit to paste a partial number (7, 11, 12, 13 or 17 digits) and get the complete barcode back. For 12-, 13- and 14-digit codes the GS1 prefix is also decoded, showing which GS1 member organisation issued the number — note that this indicates where the company registered, not where the product was manufactured. Paste a whole list into the bulk box to check hundreds of codes at once and export them as CSV. Everything runs in your browser with plain JavaScript — no barcode numbers are uploaded.
Frequently asked questions
How is an EAN-13 check digit calculated?
Take the first 12 digits and multiply them alternately by 1 and 3, so that the digit immediately left of the check digit always gets weight 3. Add the products together, then subtract the total from the next multiple of ten. For 400638133393 the weighted sum is 89, so the check digit is 90 - 89 = 1 and the full barcode is 4006381333931. The tool shows this whole calculation row by row.
Which barcode formats does this checker support?
Every GS1 number that uses the modulo-10 check digit: EAN-8 (GTIN-8), UPC-A (GTIN-12), EAN-13 (GTIN-13, including ISBN-13, ISMN and ISSN codes), GTIN-14 / ITF-14 shipping cartons and 18-digit SSCC pallet labels. Enter the complete number to verify it, or switch to calculate mode and enter the number without its last digit to get the check digit.
Are my barcode numbers uploaded anywhere?
No. The whole calculation runs in your browser in JavaScript, including the bulk list and the CSV export. Nothing is sent to a server, there is no account and no logging, so you can safely check unreleased product GTINs. The page also keeps working offline once it has loaded.