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GTIN Check Digit Calculator.

Calculate and validate GS1 GTIN check digits.

On-device calculationNo signup
01

Set your values

Results update as you type.

Complete GTIN

036000291452

FAQs

How does the gtin check digit calculator work?

Enter the requested values to see a deterministic result. Assumptions are explicit and no live market or tax data is fetched.

Use Cases

Verify barcode accuracy

Before printing barcodes, use this calculator to confirm that the check digit is correct, preventing scanning errors and supply chain issues.

Example: Check the check digit for a GTIN-13 like 400638133393.

Generate check digits for new products

When creating a new product number, use this tool to generate the correct check digit to ensure the barcode is valid.

Example: Calculate the check digit for a GTIN-12 starting with 012345678905.

Frequently Asked Questions

What is a GTIN check digit?
A GTIN check digit is the last digit of a GTIN (Global Trade Item Number) that is calculated from the other digits using a specific algorithm. It helps verify that the number is correctly composed and reduces errors in data entry and scanning.
How is the GTIN check digit calculated?
The check digit is calculated using the modulo 10 algorithm. Starting from the rightmost digit (excluding the check digit), multiply every second digit by 3, and the others by 1. Sum these products, then the check digit is the smallest number that, when added to the sum, makes a multiple of 10.
Can I use this calculator for GTIN-8, GTIN-12, GTIN-13, or GTIN-14?
Yes, this calculator works for any GTIN length. Simply enter the digits without the check digit, and the calculator will compute the correct check digit for that length.

Tips & Common Mistakes

Tips

  • Enter the GTIN digits without the check digit. The calculator will compute the missing last digit.
  • Double-check the number of digits you enter; the check digit calculation depends on the length.
  • Use this tool to validate existing barcodes by comparing the calculated check digit with the last digit of the barcode.
  • Remember that the check digit is not arbitrary; it is mathematically derived to catch common errors.

Common Mistakes to Avoid

  • Including the check digit in the input. The calculator expects the digits without the check digit.
  • Using the wrong length. Ensure you enter the correct number of digits for your GTIN type (e.g., 12 for GTIN-12, 13 for GTIN-13).
  • Misinterpreting the algorithm. The multiplier pattern starts from the rightmost digit of the input, not the left.

Last updated: August 13, 2026