Credit rating effectNot to mention what that debt could potentially do to your credit rating. "Total personal debt should not exceed 36 percent of your total income," says Gelb.
Keeping the debt-to-income ratio in mind, it's also important not to miss payments. "Missed payments are trouble," he says. "A representative of Citibank said if you don't pay within 30 days, they report that to the credit bureaus."
When it comes to buying durable goods that won't contribute to wealth generation, Bach offers a basic rule of thumb. "My grandma used to say that if you're going to buy something that doesn't go up in value, and you can't afford to pay cash, then you can't afford it."
Exacerbating the bad debt factor is that people will apply for store credit for the savings offers that say if you open a credit card account today, you can take 10 percent to 20 percent off the cost of your purchase. What people often don't realize is how much of that savings will be destroyed by the high interest rate on the card if they fail to pay for the items immediately.
"You can open a store credit card account," says Bach, "and what they're not telling you is that after the first few months, the rate jumps to 20 percent or greater."
Driving into debtAnother bad debt area is auto debt. While most people need an automobile, and the ultimate cost of an auto is higher than many people can pay in one lump sum, the way people go about it -- namely, purchasing more car than they need -- turns it into bad debt.
When is it worth it?
"What we would normally consider bad debt can turn into good debt in certain circumstances," says Catie Fitzgerald, a personal finance coach and registered investment adviser in Henderson, Nev. "If you use debt to buy a car that gets better gas mileage than your old vehicle, you could end up better off financially."
Bach considers auto debt a Catch-22. "People borrow to buy cars before homes," says Bach, "and that's unfortunate. For most people, their first major loan is a car loan. That's guaranteed to go down in value. So you really want to borrow less. For example, instead of rushing out to borrow to buy a $50,000 BMW, you'd be better off buying a $25,000 car."
The best debtThe best type of debt is debt that builds wealth over the long run, and the No. 1 example of that is mortgage debt.