Example: Paying off a $3,000 debt via a balance transfer
You have an outstanding balance of $3,000 on a credit card with a purchase rate of 19.0%. You're trying to pay it off in 2 years.
Using a credit card repayment calculator, you'd have to pay $151 a month to reach this goal. You'd end up paying $629 in interest.
Instead, you apply for a new card with a 0% balance transfer offer for 24 months, with a 2% balance transfer fee. The fee works out to $60.
Your application is approved. You move the balance onto the new card. You decide to keep paying $150 a month off the card balance. But now you pay no interest, so you repay the debt faster.
You pay the balance off in 20 months rather than 24 months, and you pay no interest. Minus the $60 balance transfer fee, you've saved $569.

