EAN-13 Check digit example error?

topics related to linear barcode formats such as Code 39, Code128, Interleaved 2 of 5 (ITF25), UCC/EAN-128, UPC-A, UPC-E, EAN-13, EAN-8, GS1 Databar etc.

EAN-13 Check digit example error?

Postby dmontroy on Fri Oct 08, 2010 3:27 pm

Trying to understand the check digit calc for EAN-13 I notice the examples sheet on the website [http://www.morovia.com/education/utility/upc-ean.asp] shows the odd and even position of digits to be just the opposite from the other barcodes, is that right? Shouldn't the 1st, 3rd, 5th etc digits be the odd digits of a number and 2nd, 4th and 6th be the even digits?

In the example for number 101742256780 The numbers being added as the odd numbers in step 2 is 0+7+2+5+7+0 *3 =63 From my point of view it should have been 1+1+4+2+6+8 *3 =66.

In step 3 it adds all the even position digits and uses 1+1+4+2+6+8 =22. I believe it should have been 0+7+2+5+7+0 =21.

Step 4 says to sum the results of step 3 and 4 but probably meant sum the results of step 2 and 3. In step 4 the example shows 63+22=85. I come up with 66+21=87

Step 5 says to Divide the results by 10 and the check digit is the number to add to the remainder to get 10. The example starts with 85 / 10 giving a remainder of 5. 10 - 5 = 5. I come up with 87/10 giving a remainder of 7. 10 - 7 = 3. Yet when I put the number in the website calculater it shows the check digit to be 5, the same as the example. Do different symboligies actually change which digits are odd and which are even? Is the example wrong and if so is the calculator program wrong too?
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Re: EAN-13 Check digit example error?

Postby glitch on Fri Oct 08, 2010 10:22 pm

The position assignment starts from right to the left, with the right most digit odd position. Some docs may say otherwise for example counting from left to right, they are also correct in some cases (for example, UPC-A) but not universally correct.

Our algorithm applies on all mod-10 cases - UPC-A, EAN-13, SSCC-14.
The information above is provided "AS IS", with no warranties, and confers no rights.
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