Say your pet swallows something, your car breaks down or you need to replace your cellphone ASAP — if you don't have the money in your bank account, how will you pay for it? Ideally, you have an emergency fund to cover unexpected expenses, but if not, a credit card can come in handy. Don't let that balance hang out too long — you can end up paying a lot of money in interest the longer you wait to pay off that debt. You can use use this credit card payoff calculator to figure out how long it will take you to pay off your credit card debt.