Internet Marketing, Search Engine Optimization blog.
Equation to calculate PageRank (PR) was published by Google long back when they where developing PR, it’s as follows:-
PR(A) = (1-d) + d(PR(t1)/C(t1) + ... + PR(tn)/C(tn))
't1 - tn' are pages linking to page A,'C' is the number of outbound links that a page has,'d' is a damping factor, usually set to 0.85.
But now Google uses a variation of it, no one out side Google knows about the variation. It doesn't matter though, as this equation is good enough