1. What is GS1 Check Digit?

The GS1 check digit is a single digit added to the end of a GS1 identification number (like those used in bills of lading) to ensure data integrity. It helps detect errors in data entry or transmission.

2. How Check Digit Calculation Works

The calculator uses the standard GS1 check digit formula:

Where:

• sum — The weighted sum of the first 17 digits
• % — Modulo operation (remainder after division)

Calculation Steps:

1. Assign weights: Starting from the first digit, alternate between 1 and 3
2. Multiply each digit by its weight
3. Sum all the weighted digits
4. Calculate the check digit as (10 - (sum % 10)) % 10

3. Importance of Check Digit

Details: The check digit is crucial for validating GS1 numbers in bills of lading and other identification systems. It helps prevent errors in logistics, inventory management, and supply chain operations.

4. Using the Calculator

Tips: Enter the first 17 digits of your GS1 number (without any check digit). The calculator will compute the correct check digit and display the complete 18-digit number.

5. Frequently Asked Questions (FAQ)

Q1: Why is the check digit important in bills of lading?
A: It ensures accurate tracking and identification of shipments throughout the supply chain, reducing errors in logistics.

Q2: What types of errors can the check digit detect?
A: It can detect single-digit errors and most transposition errors (swapped adjacent digits).

Q3: Is this the same as UPC or EAN check digits?
A: The calculation method is similar but not identical. This calculator specifically follows the GS1-18 standard used in bills of lading.

Q4: What if my number has less than 17 digits?
A: GS1 numbers for bills of lading typically require 17 digits plus the check digit. Other formats may require different calculations.

Q5: Can I validate an existing 18-digit number?
A: Yes, calculate the check digit from the first 17 digits and verify it matches the 18th digit.