Credit Card Equal Payment by Payoff Time Calculator View Calculator Enter the loan balance, interest rate, loan length, and monthly payment and this calculator will analyze your loan. You will see how long you've been paying and how much you've paid to date on your loan, as well as how much time is remaining and how much more is to be paid.Just enter your loan balance, interest rate, current monthly payment, and the additional amount you will pay each month and the calculator will compare the payoff time and interest charges for the remainder of the loan. Learn more about putting this calculator or other calculators on your website.