GTIN Check Digit Calculator

code
type
Finance

Calculate and validate GTIN/UPC/EAN check digits using the Luhn algorithm. This tool helps retailers, e-commerce platforms, and logistics companies generate correct barcodes and validate product codes for POS systems and shipping.

Formula

Luhn Algorithm: Sum(odd-positioned digits × 3 + even-positioned × 1); Check digit = (10 - (sum mod 10)) mod 10
  • Positions counted from RIGHT to LEFT
  • GTIN-12 (UPC-A): 11 digits → calculate 12th check digit
  • GTIN-13 (EAN): 12 digits → calculate 13th check digit
  • GTIN-14 (SSCC): 13 digits → calculate 14th check digit
  • Algorithm detects ~99% of single-digit errors

EAN-13 Product Code

Inputs
  • Product Code (without check digit): 978014300723 code
  • GTIN Type (12=UPC-A, 13=EAN, 14=SSCC): 13 type

ISBN 978-0-14-300723 (book code). Input first 12 digits → calculator generates 13th check digit → creates valid EAN-13 barcode for retail systems.

Frequently asked questions

What's the difference between UPC, EAN, and GTIN?
GTIN is the standard family. GTIN-12 (UPC-A) is used in US/Canada, GTIN-13 (EAN) is international, GTIN-14 (SSCC) is used for shipping cases.
Why is the check digit important?
It detects ~99% of barcode scanning errors. Without it, wrong products could be scanned, causing inventory and sales issues.
Can I validate an existing barcode?
Enter all digits except the last one as your code, then compare the calculated check digit to your barcode's last digit. If they match, the barcode is valid.