UPC–A Check Digit Calculator

The last digit of an UPC–A barcode is a check digit that is used for human transcription error detection. Here it is marked with a red square:

The location of check digit in UPC-A barcode

Check Digit Formula

To compute the check digit follow the simple rules:

Check Digit Calculator

Enter the barcode number into the field below to compute the check digit and see the maths behind:

Calculate

Here goes the check digit calculation for barcode :

  1. The digits in odd positions are: , their sum is , multiplied by 3 it is ;
  2. The digits in even positions (except the last one) are: , their sum is , added to the number above it is ;
  3. Dividing  by 10 gives us  as a reminder;
  4. It is not zero, so subtracting it from 10 to get the check digit: .
  5. It is zero, so just using it as is.

The check digit is ""

If you work with barcodes, have a look at our barcode generator which will save you much more time than this calculator.

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More Barcode Tutorials

Installation

Basics

UPC Barcodes

Other Barcodes

Export

Automation

Other