All you have to do is highlight on the left what you want to convert from and highlight on the right what you want to convert too and when you enter the number at the bottom , it will automatically give you the answer. Very easy to use.
The lock that came out of the desk has a 13/16 hole. Just trying to make sure what I order will fit. The original lock came from a old computer desk company with stuff made in China. No longer in business.