NDC Barcode Check Digit Calculator

The final digit of the NDC barcode is a check digit that helps detecting human transcription errors. Here the check digit is shown with a red mark:

The location of check digit in NDC barcode

Check Digit Formula

As NDC barcodes are based on UPC–A barcodes, the check digit computation algorithm is pretty much the same. To compute the check digit of NDC barcode follow the rules below:

  1. Take all the digits in odd positions, add them and multiply by three;
  2. Take all the digits in even positions (except for the last one) and add to the number you got above;
  3. Divide that number by 10 and take the remainder;
  4. If the remainder is not 0, subtract it from 10.
  5. That’s it.

Check Digit Calculator

To save time on doing the math, simply enter the barcode numbers into the field below and we’ll do the job for you:


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 remainder;
  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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