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This tool is for calculating check digits for barcodes from incomplete barcodes. For validating complete barcodes, use our Barcode Validator. For generating barcodes as images, use our Barcode Generator.
Amazon FBA Barcode Check Digit Calculator
Calculate check digits for your Amazon FBA product barcodes. When creating new UPC or EAN codes for Amazon listings, you need the correct check digit. Our bulk barcode calculator helps Amazon sellers:
Complete partial barcodes: Add missing check digits to your product codes
Verify GS1 prefixes: Ensure your company prefix generates valid barcodes
Bulk processing: Calculate check digits for entire product catalogs at once
Essential for Amazon FBA sellers, retail product managers, and anyone working with GTIN, UPC, or EAN barcodes in e-commerce.
How to Use the Barcode Calculator
To calculate barcodes for Amazon FBA or any other purpose, paste barcodes without their check digits into the input field. You can paste multiple barcodes at once. Separate each barcode with a new line.
Paste your barcodes into the input field
The calculation happens automatically
In the results table, you can see both the incomplete and complete barcodes side by side.
Copy, download and take additional actions like generating barcode images on all or some of the results.
How to calculate a barcode
A barcode is calculated by calculating the last digit (known as check digit) from the other digits.
Input is without check-digit:
0 4 9 0 0 0 0 8 1 3 8
Add all of the digits in the odd positions (starting from the left)
0 + 9 + 0 + 0 + 1 + 8 = 18
Multiply the sum by 3
18 x 3 = 54
Add all of the digits in the even positions
4 + 0 + 0 + 8 + 3 = 15
Add the odd position result and the even position result
54 + 15 = 69
Find the number that, when added to the result, makes the total a multiple of 10
69 + ? = 70
The check digit is 1
69 + 1 = 70
049000081381
Supported barcode types
This tool supports the following 4 barcode types:
UPC-A
12 digits
Universal Product Code (UPC) with 12 digits
UPC is a 12-digit barcode used extensively for retail packaging in the United States. UPC codes are also used in Canada, the UK, Australia, and other countries. UPC codes always have exactly 12 digits.
GTIN/EAN-13
13 digits
Global Trade Item Number (GTIN) or European Article Number (EAN) with 13 digits
GTIN-13 is used for products sold in Europe and other countries. EAN-13 is essentially the same thing, but specifically an EU standard. GTIN-13 codes are used in the US and Canada for products sold at retail point of sale. GTIN-13 codes always have exactly 13 digits.
GTIN-14
14 digits
Global Trade Item Number (GTIN) with 14 digits
GTIN-14 is used for products sold at retail point of sale. Typically this format is used for multiple product packaging, cases and pallets. GTIN-14 codes always have exactly 14 digits.
GTIN/EAN-8
8 digits
Global Trade Item Number (GTIN) or European Article Number (EAN) with 8 digits
GTIN-8 is used for products sold at retail point of sale. EAN-8 is essentially the same thing, but specifically an EU standard. Typically this format is used only for smaller products where space to print the barcode is limited. GTIN-8 codes always have exactly 8 digits.
Mastering this tool
Learn about check digit calculation - If you click on a barcode in the results table, you can choose to see the full calculation process. This is a great was to learn yourself how to calculate barcodes.
Barcode lookup - In the same row context menu, choose to lookup more information on the barcode or generate a barcode image.
Share your results - Share your results with your friends and colleagues. Clickand share a link to this tool and optionally include your input and settings as well.
Contribute - We are always looking to improve. If you have any feedback or suggestions, please use the feedback buttonto let us know. We read every feedback and use it to improve this tool.
The Best Barcode Calculator
Our Barcode Calculator is simple to use, yet still uniquely powerful.
Easy - Sometimes you just need a simple tool with no fuss. Our Barcode Calculator is just that. But for those times when you need more, it also has powerful features such as bulk processing, additional barcode information and automatic barcode type detection.
Fast - Our Barcode Calculator is fast. Start now and instantly get calculated. No waiting, just instant results.
Ad free - Our Barcode Calculator is free from ads. Many other tools are cluttered with ads, but not this one.
Frequently Asked Questions
Common questions about barcode check digit calculation, algorithms, and different barcode formats.
What is a barcode check digit?
The check digit is the final digit of a barcode, calculated from other digits using an algorithm. It detects transcription errors: if any digit is wrong, the check digit won't match. For UPC/EAN, it uses modulo-10 arithmetic. The check digit is automatically verified when a barcode is scanned.
How to Calculate EAN-13 Check Digit
Calculate the check digit for EAN-13 barcodes using the modulo-10 algorithm.
Sum digits in odd positions (1,3,5,7,9,11)
Sum digits in even positions (2,4,6,8,10,12) and multiply by 3
Add both sums together
Check digit = 10 minus (sum mod 10). If result is 10, check digit is 0
How to Calculate UPC-A Check Digit
Calculate the check digit for UPC-A barcodes using the weighted sum method.
Sum digits in odd positions (1,3,5,7,9,11), multiply by 3
Add sum of even position digits (2,4,6,8,10)
Find modulo 10 of total
Subtract from 10 (if result is 10, use 0). Position counting starts from the left with the first digit as position 1
How is an ISBN check digit calculated?
ISBN-13 uses EAN-13 checksum: alternating weights of 1 and 3 for each digit, summed, with check digit making total divisible by 10. ISBN-10 (older format) uses weights 10-1 and modulo 11, sometimes producing 'X' as check digit (representing 10). ISBN-13 is now standard for book barcodes.
How do I calculate a GTIN check digit?
GTIN (Global Trade Item Number) includes GTIN-8, GTIN-12, GTIN-13, and GTIN-14. All use the same modulo-10 check digit algorithm. Right-to-left, multiply alternating digits by 3 and 1, sum all results, subtract from nearest multiple of 10. GTIN check digit calculators support all formats automatically.
