The information you need depends on how detailed you want your estimate to be. Most basic mortgage calculators require the home price or loan amount, down payment, interest rate, and mortgage term. If you want a more complete estimate of your monthly housing cost, you may also need property taxes, homeowners insurance, PMI, HOA fees, or other applicable expenses. For an existing mortgage, you may instead need your current loan balance, interest rate, remaining term, and any planned extra payments. Having accurate numbers makes the estimate more useful, but you can also begin with approximate figures when you’re still comparing homes or loan options. A mortgage calculator can help you test different scenarios and see how changing one factor affects the estimated payment. For a more detailed estimate, you can use a calculator designed around the specific costs you want to include.
