There are two utility functions that sometimes are needed while conducting an inventory.
When you have only the 11 UPC digits, sometimes it is necessary to calculate the checkdigit. Enter the 11 digits and click Calc Check Digit button.

11 Digits UPC

Calc Check digit

CD

If you have a short UPC, enter the 6, 7, or digits and it will expand to 12 digits, including UPC check digit.
When entering 6 digits, it is assumed a leading 0

8 digits

Expand

CD