Setting a goal for paying off a mortgage, auto loan, credit card or personal loan makes sound financial sense. Some loans, such as a mortgage or car loan have defined repayment periods. Others do not and are revolving lines of credit with variable interest rates. To reach a debt repayment goal, you will need to know what you need to pay each month, and if your interest rate can vary. You also might want to compare it to your current repayment schedule if your loan has one to see how helpful reaching that goal might be.