Check digit calculator
Enter a barcode number without its last digit and we will calculate the GS1 check digit.
Every UPC, EAN and GTIN ends in a check digit. Scanners recalculate it from the other digits and reject the scan if it does not match, which catches most typing and printing errors. The digits are multiplied alternately by 3 and 1, starting from the right, and added up; the check digit brings that total to the next multiple of 10.
Frequently asked questions
What is a check digit?
It is the last digit of a UPC, EAN or GTIN. It is calculated from the other digits so that scanners and systems can spot a mistyped or misprinted number.
Does the check digit work the same for UPC-A and EAN-13?
Yes. GS1 uses the same modulo-10 method for EAN-8, UPC-A, EAN-13 and GTIN-14, always weighting digits 3 and 1 from the right.
Can I make my own barcode number with this?
No. A correct check digit only makes a number well-formed; it does not make it yours. Product numbers have to come from GS1 or a legitimate reseller with a transfer certificate, otherwise they can clash with someone else's product.