1. What is GTIN-14?

GTIN-14 (Global Trade Item Number) is a 14-digit identifier used for trade items at various packaging levels. It includes a check digit for validation purposes.

2. How Check Digit Calculation Works

The calculator uses the GS1 standard algorithm:

Where:

• sum — Weighted sum of first 13 digits
• weighting — Alternate between 1 and 3 starting with 3 for first digit

Calculation Steps:

1. Multiply each digit by 1 or 3 (starting with 3 for first digit)
2. Sum all the weighted digits
3. Find the smallest number that when added makes a multiple of 10

3. Importance of Check Digits

Details: Check digits help detect errors in GTIN numbers that might occur during data entry or transmission. They validate the integrity of the number.

4. Using the Calculator

Tips: Enter the first 13 digits of your GTIN-14. The calculator will compute the 14th check digit and display the complete valid GTIN-14.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between GTIN-14 and other GTINs?
A: GTIN-14 is used for cases/pallets, while GTIN-12 (UPC), GTIN-13 (EAN), and GTIN-8 are for individual products.

Q2: Does this work for other GTIN formats?
A: The calculation method is similar, but the starting weight differs based on length (GTIN-12 starts with 3, GTIN-13 starts with 1).

Q3: Can I validate an existing GTIN-14?
A: Yes, apply the same calculation to the first 13 digits and verify it matches the 14th digit.

Q4: Why does the weighting alternate?
A: Alternating weights helps detect transposition errors (swapped digits) which are common in manual entry.

Q5: Are there other check digit algorithms?
A: Yes, different systems use different algorithms (Luhn for credit cards, Mod 11 for ISBNs, etc.).