How is Google PR Calculated ? I have the equation but I am no sure if it is right !!!

How is Google PR Calculated???!

I have found an equation that I will share with you..

and I hope everybody to share his info too..

PR(A) = (1-d) + d(PR(t1)/C(t1) + … + PR(tn)/C(tn))

A is the page whose PR is being calculated.

t1 - tn are the pages which are linking to the webpage A

C is the number of outbound links on that page

d is a damping factor and its default value is 0.85

The value for ‘d’ varies and Google also uses other variations of the formula given above.

A simpler version of the formula can be:

Page’s PR = 0.15 + 0.85 * (a share of the PageRank of every page that links to it)

Since Google PR is equally divided among the outbound links of a page, the share of PR passed to every site is

( PR of page t1 / Outbound links of page t1 ) * ( % of the amount of PR to be passed)

Hence, the % value is taken as 0.85 since a page ‘votes’ an amount of PageRank onto each page that it links to, which is shared equally among all the pages that it links to.

From this formula, we can see that a link from a page with PR 5 with 10 outbound links is worth more than a link from a page with PR 8 with 100 outbound links.

5/10 = 0.5 whereas 8/100 = 0.08

When searching for link partners, the PageRank of a page of the linking site should be taken into consideration as well as the number of outbound links on that page. The more outbound links a webpage has, the less PR value will be passed to your webpage.

I will appreciate some Rep's

 

hmmm ... nice equation !!

 

Good info...rep added You might also check out the THIS ARTICLE by Smashing Magazine. Just about all the info you'll ever need to know about PR.

 

looks like greek to me

 

Might also want to give a nod to Larry and Sergey who created the formula, too

 

lol, not quite that simple

 

Thanks

 

There is a problem with this conclusion:

If PR was passed as in the formula given, 10 links from good PR1 pages could make your page a PR7 (even if they were all from the same site). In reality, as we know, you would need an enormous number of PR1 links to become PR7.

This is because the PR(A) being calculated above is not the same as the toolbar PR. It is on a scale of some kind - perhaps assume a scale of 1 - 10,000,000, the real number isn't important. After calculation, that whole scale is then split into, say,12 categories (supplemental, and PR0-PR10) and toolbar PR is attributed to each page according to its category.

So you might need a PR(A) of 25,000 to be a PR4 or PR(A) of 7,000,000 to be a PR8.

Presumably certain links are also devalued - eg a sitewide link from a site with 100 PR3 pages will not pass the same PR as links from 100 different PR3 sites.

People often say that each PR is about 5-6 times more 'valuable' than the one before, and needs 5-6 times more links to get it. That suggests that a link from a PR5 page with 1 link has the same PR value as a PR6 page with 5 links or a PR8 page with 125 links. Again very approximate, because a site at the bottom of the PR6 scale, for example, will be quite a bit weaker than a site at the top of the PR6 scale.

Cheers

 

good equation, I didn't know before
thanks

 

Actually, if those 10 PR1 pages plus the page they were linking to were the only pages on the web, I would actually expect at least a PR7 to result, possibly higher.

The bit that's left out of the OP's description is that PR is a function of the number of pages that exist... it is entirely dependant on the number of total pages on the web, and the number of cumulative links it takes to receive a given PR is a logarithmic percentage of the total linkage in existence. From the white paper:

You were definitely right on the bit you quoted however:

The PageRank that is calculated by that equation represents the total recursive sum of all links pointing to a particular page, and assumes every page starts with some default value (I think 0.15). The 0-10 number you see on the toolbar is actually a percentile number representing how many relative pages that one page has more link juice than. Look at this image:



According to this, it would take about 16,803 PR1 links to reach a PR5. If you assume the dampening factor of 0.85 and say that the page has 10 links on it, the getting a link from this page would be the same as getting 1,428 PR1 links pointed at you:

0.85(16,803/10) = 1,428.255

Now, it also says it would take approx. 2,795,522 links to reach PR8... therefor, if that PR8 page had 100 links on it, being one of those would be the similar to having 23,761 PR1 links pointed at you:

0.85(2,795,522/10) = 23,761.937

Now, obviously it has a little more to do with it than that, and Link Recursion Depth comes into play, so not all PR5's (or PR8's) are created equal, but you get the general idea.

-Michael

 

So if you have 3 links on a PR5 site and nothing else, what will you be at after an update?

 

Thanks man good info.

 

Actually no one know's apart from google.

So people should probably stop posting random theories

 

We all are making guess on the page rank, some tools are also give us and idea of the page rank, but what is the right way to calculate the page rank, no one is know, because some site has less page rank but has a lots amount of the back link, while some site has less back links and has good page rank see this site has http://www.marketstar.com only 28 back link and has PR 5 in this 15 back links are from its own pages, and http://www.niceone.ie/websitedesignireland/ this site has 57 back link while its page rank is only 4 so I did not think that by any method we can calculate the exact Page rank , its still secret as death, so we can not predict exact next page rank of our website on the basis of the number of back link or PR of the back links.

Keep in Touch
Ambrish Shrivastava.

 

it is not the number of the backlinks.. it the PR of these links..

 

I have a website with toolbar PR5 and only one PR6 backlink, actually is a link exchange, because I have a link to its website too. Someone could tell me how G calculated this for my website? Only they know this as amnezia said. All we need to do is optimize it better and have a valuable contents (IMO).

 

nice equation but it woulkd be more nice if it had a tool to calculate it ,
where we just had to fill the values

 

its not greek dude
because if it was greek i would be ale to understand it!

 

This article is based on an original article by Google founders:

Google PR explained

Although it says that noone knows for sure (except Google) how it is calculated today, the principles have stayed the same. And knowing the principles is enough for you to know what to do to get a higher PR.