Check Digit Calculator
The last digit of an EAN, UPC, GTIN or SSCC number is a check digit: it is calculated from the other digits so scanners can spot a typing mistake. Type the number without its check digit to get the full number, or type the full number to test it.
The calculation is shown digit by digit. When you are done, make the barcode with one click, or look up what a number means with the barcode validator. To convert between UPC and EAN use the UPC / EAN converter.
How the check digit works
EAN, UPC, GTIN, GLN and SSCC use the same rule: starting next to the check digit and moving left, multiply the digits alternately by 3 and 1, add the results, and the check digit is the number that brings the sum up to the next multiple of 10. ISBN-10 and ISSN use a modulo 11 rule with falling weights (an X stands for 10). Luhn, used for IMEI numbers, doubles every second digit instead.
A correct check digit does not prove a number is registered to a product. For that the company prefix must be licensed by GS1. Numbers starting with 2 are for in-store use only.