You can determine how much your mortgage payments will be. Just enter the amount you want to borrow, the interest rate, the number of payments per year, and the term (number of years). Don't forget to subtract your down payment from the cost of the home.
Most lenders will require an additional amount to cover your home insurance, real estate taxes, and PMI with the mortgage payment. The lender will then make these payments for you.
For instance, if you are making monthly payments, each payment would include 1/12 of your yearly taxes, insurance, and PMI.