Google Page Rank Explained

The term ‘Google Page Rank’ seems to be a constant source of fascination for every SEO expert and budding web site owner these days, but not everyone is clear exactly what ‘Page Rank’ is and how it affects their site. Similarly there is much confusion as to how it is calculated and the importance it has for your site. This article will look at what exactly Page Rank is, and how Google calculate it.

The name ‘Page Rank’ was created not because the calculation relates to web pages, but because it was formulated by Larry Page, one of the original creators of the Google search engine. Page Rank was originally born from the idea that links between one web page and a web page from another site were basically a vote of approval for that web page from someone else. Long before SEO experts came along with spam backlinks and tried to game the system, the basic principle was that websites, or more specifically web pages, would only be linking to other web pages if they believed that those pages were of interest or value to their readers. If people cared only about quality and their readership then they would only recommend websites that would be worth looking at. Consequently, Google took the amount of inbound links (or IBL’s) to a web page as a way of judging the importance and value of that web page and used this value, along with other calculations, to work out what position that web page merited on their search result pages (or SERP’s.)

This Page Rank was calculated to be a measurement between 1 and 10 with 10 being the highest value Page Rank a site could achieve. There are now hundreds of free plugins out there that will sit in the toolbar of your browser (such as Firefox, Internet explorer or Safari) and can tell you the Page Rank of any site you visit. If a site has a PR of 0 then it is brand new and has not built up its ‘reputation’ with the Google search engine. On the other hand if a site has a Page Rank (or PR) of anything above 4 or 5 then you know it has been around for some time and that Google sees it as a trustworthy site. As mentioned above, the main way that Google has traditionally calculated this Page Rank is through Inbound Links. Over the years these have become known as ‘backlinks’ and there are now plugins and various SEO utilities that can display the number of backlinks that Google counts as going to the page you are looking at. Another way of doing this, without using plugins, is to type “link:http://www.yourURL.com” into the Google search box replacing yourURL.com with the name of the site you want to research. It used to be believed that Google only included pages with a Page Rank above four but recently lower PR links have been included. Because Google are secretive about their exact calculations, the best thing to do is see the list of backlinks as a representative sample.

How then is Page Rank calculated? In essence it works on a division of all of the PR from the backlinks to your page as well as the internal links within a site. The most important point to realize when it comes to backlinks, and something most people don’t know, is that the PR points passed to your page will be dependent on not only the PR value of the page they come from but also the volume of outbound links on a page. Pages pass on about 85% of value to pages they link with; consequently if a PR6 page has only one outbound link then it will pass 85% of its PR6. However, if it has a number of other links, internal or external, then that 85% will be significantly diluted.

This gives a rough idea of how PR is calculated, although there are a number of other variables. The point to remember is that in order to improve your PR you either need a few links from sites with higher (or at the very least equal) PR than yours, or hundreds, if not thousands of links from sites with a lower PR than yours.