Ebay Feedback Calculator

Millions of people buy and sell various things on Ebay. Occasionally someone will get mad and leave a negative comment.  I've gotten one and have called Ebay a few times trying to figure out how many sales I need to make to get my percentages up to at least 99.5 or higher. 

A couple months ago and Ebay representative told me that their was a formula and as the conversation continued I forgot to get it.

Today searching the internet I have found the answer.

Here it is.

Hope this helps anyone and everyone. No registration no log in just the formula.
Thank you