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GTIN & product identifiers

GTIN Check Digit Calculator

Calculate the last digit of a GTIN, UPC or EAN using the GS1 modulo-10 formula. Enter only the digits before the check digit: 7 for GTIN-8, 11 for UPC-A, 12 for EAN-13, or 13 for GTIN-14.

Use 7, 11, 12 or 13 digits.

Try an example:
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The calculated check digit and complete GTIN will appear here.

Private by design: Your input is processed locally in your browser and is not uploaded to ProductPassKit.

Calculate a GTIN check digit in seconds

Enter the data portion without its final digit. The calculator detects the intended length and returns both the GS1 modulo-10 check digit and complete GTIN. For an existing full number, use the GTIN Validator instead of this calculator.

How many digits do you need to enter?

Target identifierEnter data digitsTotal digits with check digit
GTIN-8 / EAN-878
GTIN-12 / UPC-A1112
GTIN-13 / EAN-131213
GTIN-141314

Worked example: calculate an EAN-13 check digit

400638133393 + 1 = 400638133393112 data digits + check digit 1 = complete GTIN-13.
  1. Start with 400638133393, the 12 digits before the final check digit.
  2. From the rightmost data digit, multiply the digits alternately by 3, 1, 3, 1 and so on.
  3. Add the weighted products: the sum is 89.
  4. The next multiple of 10 is 90, so (10 - (89 % 10)) % 10 = 1.
  5. Append 1 to get 4006381333931.

Other structural examples: data 03600029145 gives check digit 2 (UPC-A), while 9638507 gives check digit 4 (EAN-8). For the mathematical explanation, see how to calculate GTIN check digits step by step.

When this result is not enough

The calculated digit ensures arithmetic consistency with the supplied data portion. It does not prove the number has been legitimately issued or that a product uses it. For spreadsheet errors and multiple values, see why a GTIN can fail validation and the CSV GTIN validator.

Frequently asked questions

What is the GTIN check digit formula?

Starting at the rightmost data digit, multiply alternate positions by 3 and 1, add the products, then subtract the sum modulo 10 from 10 and take the result modulo 10. The last digit makes the total a multiple of 10.

How many digits should I enter for a UPC-A check digit?

Enter the first 11 digits only. The calculator returns digit 12, completing the UPC-A / GTIN-12 number.

Should I include an existing GTIN check digit?

No. Enter only 7, 11, 12 or 13 data digits. If you already have a complete 8, 12, 13 or 14-digit GTIN, use the GTIN Validator instead.

Does the calculator assign or verify a GS1 number?

No. It performs a mathematical calculation only. Identifier allocation, licensing, product ownership and barcode quality are separate checks.

Standards references

Use these primary GS1 sources for implementation requirements beyond this browser-based utility.