go to CNN.com, click on buisness, click personal finance and go to real estate, then calculators. It gives you a whole bunch of choices, but I think the first one, estimate my payments, is what you are talking about.
Is it the best calculator in the world, no. Should you buy based on what a free calculator online said, no. Will it help you get familiar with costs? yes, if you use it well. When you get better at it, build your own in excel that better fits your needs if you so desire.
