# UPC-A Barcode Check Digit Calculator

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

## Check Digit Formula

To compute the check digit follow the simple rules:

- Take all the digits in odd positions, add them and multiply by three;
- Take all the digits in even positions (except for the last one) and add to the number you got above;
- Divide that number by 10 and take the reminder;
- If the reminder is not 0, subtract it from 10.
- 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 :

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