Calculate Damm Check Digit
Enter a number into the box and the check digit will be appended below. Note non-digits will be ignored but left in place.
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. Note non-digits will be ignored but left in place.
Enter Number To Verify