I've seen a formula for PageRank posted on Internet websites and forums but have failed to see anyone give a satisfactory explanation of the formula. The formula appears so complex you would probably have to be a mathematician to even have a chance to decipher it anyway. It looks something like this:

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

I will attempt to explain it for you in plain English. Basically it works like this. The more links that point to your website the higher your PageRank will be. The higher the PageRank of the referring page that has your link on it, the more PageRank you receive from Google. For every outgoing link that a page has, the value of those links drop. So for example, a link from a page with a PageRank of 4, and only 3 other links, is worth more than a page with a PageRank of 5 and 100 links. It is also believed that Google assigns more value to a link that comes from a site with similar content. So as you can see, there are many variables when calculating PageRank.