How is Page Rank calculated
How is page Rank Calculated
Google Page Rank is a score that google give to each and every page that they have indexed on the internet. The Page Rank shown on the toolbar varies from 0/10 to 10/10 (or the terrible greyed-out ’site-banned’ score), and is intended to represent the relative importance of a site or page.
The page rank is calculated as a function of the other pages that link to a page, and is a result of the page rank of that page and the number of other links on the page. Very broadly the PR (page rank) passed by a link is calculated as:
0.85 * page rank of the page with the link on / number of external links on the page
But because google don’t really use a scale of 0-10, rather a scale of perhaps 0 - 1,000,000, which they then convert to a score out of 10 for the purposes of the google toolbar, it is not practical to use this formula to estimate our own page rank.
So having 10 links from PR1 pages will not result in PR of 0.85*10=8.5! Rather, the ‘real’ google PR will be based on 10 links from pages with PR of, say, 100, giving a PR of perhaps 850. This then converts to a toolbar PR of 1 or 2.
Note that the exact scores google uses aren’t known, so we can’t be more accurate. These are just demonstrating the general idea.
Note: the page rank used internally by google is updated more or less continuously as they become aware of new links, pages etc. The Toolbar Page Rank based on this is only updated intermittently - every few weeks or months according to Googles whims. And just to put paid to a couple of common Page Rank myths and misunderstandings:
No, the date of the next ‘toolbar export’ can not be forecast or guessed
No, future page rank forecasting tools can not be relied on
No, your position in the search engine results will not change because there has been a ‘toolbar PR export’