I made a formula to caculate adsense earnings, but who knows if thats anything close to how it really works
It's and excel formula, so B2 is CPC, 0.17 is around 17% what I think google pays you per click, C2 is numnber of estimated searches for a specific keyword, 0,5 is 50% click to your site on SERP if you are #1, and 0,03 is 3% CRT on your site ..
So for an example:
CPC is $2
Estimated seraches per month = 10.000
=((2*0,17)*(10000*0,5))*0,03 = $51 .. what do you think guys?