The best calculators are whatever software they filed their 2007 taxes with (turbo or taxcut). Just open the completed return and input the estimated mortgage interest and r/e taxes, then save the return under a different name. Then compare it to the return that they actually filed. That is the best way to figure one’s unique situation. As a ballpark figure I use the “T”,the “I” and the basic maintenance in the PITI, so when I figure out the principal and interest, that is the out of pocket amount, the taxes, insurance and basic maintenance are offset by the tax deduction. Don’t let anyone talk you into how great the mortgage interest deduction is, a wise man who had his house paid off once asked me “would I rather pay three dollars to the bank or one to the government?”
