Credit Card Calculator
will show you how much interest you will end up paying if you make only the minimum required payment on your credit card bill
that is, assuming you stop charging any more to it. And remember, it's not just the interest you're losing, you're also losing the interest you could be earning on that interest if you were investing it rather than paying it to the credit card companies
. This calculator
will also tell you how many minimum payments you will make before your balance is paid off. Try various input values and see how much interest you pay on your credit card purchases, or see how much difference a lower interest rate would make.