In the Google search engine, appears in front of a site with a page rank higher than another one that is better optimized. If, for example, a website is well optimized, but has Page Rank little he will not be the top in Google, and vice versa, if you have high PR and is not optimized at all. Formula for calculating the Page Rank as: PR (A) = (1-d) + d (PR(T1)/C(T1) + ... + PR(Tn)/C(Tn)) That mean: PR (Tn) - every page has a notion of self important / relevant. This is PR (T1) for continuing home to PR (Tn) for last. C ( Tn) - Each page splits its vote all links exiting this page . Index or number of links to the first page is C ( T1) and C (Tn ) for n in page for all pages . PR (Tn ) / C ( Tn) - If our page has a link to it ( backlinks ) n , dividing the vote page A will get is PR (Tn ) / C ( Tn) d (...) - All of these parts are assembled but vote to stop the influence of the other pages , this vote is "cast / ignored " by multiplying by 0.85 (factor d ) (1 - d ) - Index (1 - d ) from the beginning is a mathematical probability , so the " sum of all pages Page Rank sites to be one " add to index "lost " by d (.. . ) . It also means that if a page has no links to it ( no backlinks ) it will receive a small PR of 0.15 ( 1 - .85 ) . Briefly Page Rank could be calculated as 0.85 multiplied by the page 's Page Rank and divided by the number of links on the page.