The first step in calculating your mortgage payment, is understanding how much you can afford to borrow. This can be determined by going to How Much Can I Afford? and follow the instructions on using the Affordability Calculator. The result from that calculation will help determine your purchase price to enter in the Mortgage Calculator on this page.
You will want to take the Loan Amount from the Affordability Calculator and add your down payment amount to figure the Purchase Price you need to enter in the Mortgage Calculator below. Next, just fill in the rest of the fields and click Calculate.
The result from the Mortgage Calculator will provide you with your total monthly mortgage payment. It will include your Principal, Interest, property Tax and homeowner Insurance in one monthly (PITI) payment that you would make to your lender.
If you need, tweak the amount of your down payment or the purchase price amount until you get to your desired monthly PITI mortgage payment amount. Now you are getting seriously close to understanding how much you need to save for a down payment, what range of home prices you should be searching and to properly budget for your new home!