How to Calculate a Modulo 10 Check Character.
Modulo 10 check characters are used with various barcode symbologies. They are always used with UPC-A and EAN-13 barcodes. We get quite a number of inquiries as to how to calculate this digit. So here is the procedure.
Try this on a few UPC or EAN symbols that have the check digit already printed with the symbol, just to make sure you've got the process correct. If you've got a code with the digit already printed, make sure not to include it in your calculations. Remember, with UPC there should be eleven digits involved in the calculation. Twelve with EAN.
Copyright(c) Custom Sensors, Inc.. Created: 11/11/96 Updated: 9/10/97