Damm Algorithm Check Digit Tool

This page is meant as a very basic tool to aid users of the Damm check digit algorithm. I created this for my own uses but hope that it may be helpful for someone else too! This tool uses only client-side javascript which can be reviewed by looking at the page source.

Calculate Damm Check Digit

Enter a number into the box and the check digit will be appended below.

Enter Number To Calculate

Verify Damm Check Digit

Enter a number to test the last digit as a Damm check digit. Text below the box will display if the number is valid or invalid.

Enter Number To Verify


I strive to make creative designs and find innovative solutions to problems.

My hobbies include: electronics, 3D printing, amateur radio, photography, hiking, and wild camping.

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