Balance Transfer Calculator (Is 0% APR Worth It?)

How balance transfers actually work

A balance transfer card charges a one-time fee (3–5%, added to your balance) and pauses interest for an intro period (usually 12–21 months). The math is a race: clear the balance before the clock runs out and the fee is all you paid. Miss it, and the card's regular APR — often as high as your old one — resumes on whatever remains.

Break-even: transfer wins when saved interest > transfer fee

Worked example: $6,000 at 24%

Paying $400/month where it is: about 17 months and roughly $1,050 of interest. Transfer with a 3% fee ($180) and a 15-month 0% window: the $6,180 clears in 16 months with almost no interest — total cost ≈ $190, saving about $860. The required clear-in-time payment is $412/month; at only $250/month, much of the balance survives the window and the advantage shrinks fast.

Three rules for making transfers work

• Divide balance-plus-fee by the intro months — that payment, on autopay, is the whole strategy.
• Stop using the old card. A transfer that frees a card that refills was a debt doubler, not a rescue.
• Never miss a payment — many issuers cancel the 0% rate on a single late payment.