1. What is EAN-13?

EAN-13 (European Article Number) is a 13-digit barcode standard used worldwide for marking retail products. The last digit is a check digit used to verify the validity of the code.

2. How Check Digit Calculation Works

The check digit is calculated using the following formula:

Where:

• odd — Sum of digits in odd positions (1st, 3rd, 5th, etc.)
• even — Sum of digits in even positions (2nd, 4th, 6th, etc.)
• mod — Modulo operation (remainder after division)

Explanation: The calculation weights odd and even positions differently to detect common scanning errors like single digit errors or transpositions.

3. Importance of Check Digit

Details: The check digit ensures data integrity by allowing scanners to verify that the barcode was scanned correctly. It can detect about 90% of common scanning errors.

4. Using the Calculator

Tips: Enter the first 12 digits of the EAN-13 code (without the check digit). The calculator will compute the correct check digit and display the complete EAN-13 code.

5. Frequently Asked Questions (FAQ)

Q1: Why is the check digit important?
A: It helps prevent errors in barcode scanning by verifying the code's validity before processing.

Q2: What's the difference between EAN-13 and UPC?
A: UPC is a 12-digit system used primarily in North America, while EAN-13 is 13 digits and used internationally. EAN-13 is a superset of UPC.

Q3: Can this calculator validate existing EAN-13 codes?
A: Yes, enter the full 13-digit code and compare the calculated check digit with the last digit of your code.

Q4: What if the calculation gives 10?
A: The modulo operation ensures the check digit is always 0-9. If (sum mod 10) is 0, the check digit is 0.

Q5: Are there other barcode standards with different check digit methods?
A: Yes, different barcode standards (like ISBN, Code 128) use different check digit algorithms.