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:
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 remainder;
- If the remainder is not 0, subtract it from 10.
- That’s it.
Check Digit Calculator
Enter the barcode number into the field below to compute the check digit and see the maths behind:
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 remainder;
- 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.
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Installation
- Installation — how to install Barcode generator;
- License Activation — how to activate Barcode software with a license key.
Basics
- User Interface — Barcode user interface explained in details;
- Barcode Management — adding, renaming, cloning and deleting barcodes;
- Importing Barcodes — importing barcode images;
- Custom Texts — adding custom text elements to barcodes;
- Marks Panel — configuring border, margins and canvas of barcodes;
- Bar Width Reduction — adjusting barcodes to compensate for ink spread;
- Quiet Zone — making sure the barcodes can be scanned well.
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- EAN–13 Calculator — how to compute EAN–13 check digits.
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- NDC Barcode Check Digit Calculator — how to compute NDC check digits.
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- QR Code — how to make and configure the popular 2D barcodes;
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- Vector Barcodes — exporting barcodes to vector formats;
- Export.js — defining custom file names for exported barcodes.
Automation
- Batch Processing — how to batch–convert text data to barcodes;
- Command Line Processing — command line barcode generation.
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