In calculating your mortgage you want to know the principal, taxes and interest. Most of all you want to know what your monthly payment will be based on those numbers. Here is a calculator to give an estimate of what your payments will look like.
If you have futher questions, please consult with a mortgage professional who can advise you how to lower the payments. Yoiu can always give Brocks Real Estate a call when you are pre-approved for a mortgage at 516-385-1880