Every banks which have their online presence also have their emi calculators.
http://www.hdfc.com/calculator/emical.asp
I have used this HDFC bank's caculators for my deal. My dealer said he is giving me a loan from HDFC bank and said that he would give me a certain emi at interest rate of 13%. When I check the site and tried out the emi calculator it seemed that the deal that he was offering me for 13% actually was an emi for 14.75%.
I brought this to his notice and we then negotiated to get the rate of interest down to 13.75% and would not come anything below that.
Man, these dealers are like sharks. Beware of them. I have also created a excel sheet to calculate but would like to know how do I post the attachement in this thread.