EAN & UPC Check Digit
Compute or verify the EAN-13 / UPC-A barcode check digit.
Get the barcode check digit right
Retail barcodes end in a check digit that guards against scan and entry errors. This calculator computes that digit for an EAN-13 or UPC-A number, or verifies the one already present.
For the first 12 digits 590123412345 the check digit is 7, giving the valid EAN-13 5901234123457. A 12-digit UPC-A is handled as an EAN-13 with a leading zero, so both formats work here.
Exact and private
The weighted-sum checksum is computed in your browser, so it responds instantly and nothing you enter is uploaded.
Frequently Asked Questions
How is the check digit computed?
By weighting the digits alternately 1 and 3 from the left, summing, and taking the amount needed to reach the next multiple of ten. UPC-A is treated as EAN-13 with a leading zero.
Do I include the check digit?
Enter 12 digits (UPC-A) or the first 12 of an EAN-13 to compute it, or the full 13 to verify the one that is there.
What is this useful for?
Generating or checking retail barcode numbers before printing or entering them into a catalog.
Browse the full set of free, private, in-browser tools.