Average rank finder will help you to analyze how a website is doing by taking average rank of all of it's keywords. An average rank of a website on a day in a specific search engine is calculated as below
if a website X has keywords k1, k2, k3, k4, ...., kn and it's rank in a search engine s is rs1, rs2, rs3, rs4, ....., rsn on a day. Then the average rank of the website is calculated as
(rs1 + rs2 + rs3 + .... + rsn) / n = avs, so avs is average rank in a search engine s. Similarly we can calculate avearage rank in other search engines too.
Average rank finder has a cron script that calculate the average rank and display it for you.