Check Digit Calculator
Instantly calculate and verify check digits for EAN, UPC, GTIN, and ISBN barcodes
Every retail barcode includes a check digit — a single digit calculated from the rest of the number that lets scanners detect transcription errors. Enter the data portion of your code and we'll compute the mod-10 check digit for EAN-13, UPC-A, EAN-8, ISBN-13, or GTIN-14.
Calculator Input
Choose a barcode type and enter the data digits
Result
Calculated check digit and full code
How It Works
Pick the barcode type you're working with.
Enter the data digits (without the check digit).
We calculate the check digit using the GS1 mod-10 algorithm.
Copy the complete number for use in your barcode generator.
Common Use Cases
Verify Existing Codes
Confirm an EAN/UPC printed on a product is mathematically valid.
Generate New Codes
Complete a number when you only have the data portion.
Data Entry Validation
Build into spreadsheets and import scripts to catch typos.
EDI & B2B
Validate GTIN-14 case codes in trading partner feeds.
Self-Publishing
Confirm ISBN-13 check digit before sending to the printer.
Education
Teach the GS1 mod-10 algorithm in a hands-on way.
Technical Specifications
- EAN-13 input
- 12 digits → calculates digit 13
- UPC-A input
- 11 digits → calculates digit 12
- EAN-8 input
- 7 digits → calculates digit 8
- ISBN-13 input
- 12 digits → calculates digit 13
- GTIN-14 input
- 13 digits → calculates digit 14
- Algorithm
- GS1 modulo 10
Frequently Asked Questions
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