When you're shopping for a real estate property, there are plenty of things to consider, and the mortgage you can qualify for is just one. However, during the process you'll be evaluating a number of properties and mortgage options. The ability to "run the numbers," checking the property financing details with different mortgage and down payment options, is important.
Use the mortgage calculators on this page to help you run those numbers and try different combinations of interest rate and down payment with each home on your list. There's no substitute for knowledge and preparation.