Mortgage Refinance Comparison Calculator View Calculator Calculate and compare (formatted side by side) up to 4 mortgage refinance loans to help determine if you should refinance your mortgage. Enter your current mortgage principal and interest payment, your current mortgage balance, the new interest rate, term of the refinanced loan, points and closing costs. This calculator will then show you the new monthly principal and interest payment amount, the amount of money you can save each month and how many months you will pay on the new loan before you actually start saving money (months to break even). (Note: this calculator may show negative monthly savings and months to break if your monthly payment actually goes up. That may happen if the interest rate is higher or the length of your refinanced loan is shorter - for instance, if you refinance a 30 year loan to a 15 year loan.) Learn more about putting this calculator or other calculators on your website.