How this calculator works
Compares keeping the balance where it is with moving it: the fee is added to the new balance on day one, the intro APR applies for the promo months, then the card's regular APR takes over on whatever is left. The same monthly payment is used for both so the comparison is like for like.
- Transfer fee = balance × fee %; it is added to the new balance on day one.
- Each month: interest = balance × APR ÷ 12, using the intro APR during the promo months and the regular APR after; the same monthly payment is applied in both scenarios.
- Payment to clear it inside the intro period = the standard loan payment on (balance + fee) at the intro APR over the intro months.
Worked example
With these inputs: balance to move $6,000; current card apr 24.99%; monthly payment $300; transfer fee 3%; intro apr 0%; intro period 18; apr after the intro period 24.99%.
The result is transfer saves $1,630.56, with transfer fee $180.00 and interest after moving $30.88. Some balance will still be there when the intro rate ends. Paying $343.33 a month clears it first.
When a balance transfer is worth it
It works best when the balance is large, the current APR is high, and you can pay enough each month to clear most or all of it before the promotion ends. A 3% fee on $6,000 is $180; at 24.99% APR that balance costs well over $100 a month in interest, so the fee is usually repaid within the first two months.
It works badly when the payment is small. Whatever is left when the intro period ends goes back to a high APR, and if you keep spending on either card you can end up with two balances instead of one.
Read the offer before you move the money
Check four things: the transfer fee (often 3% to 5%, sometimes with a minimum dollar amount), how long the intro APR lasts, the APR afterwards, and whether the offer is a true 0% APR or a deferred-interest promotion. With deferred interest, interest accrues from day one and is charged in full if the balance is not paid off by the deadline — a very different deal, and one this calculator does not model.
Under federal rules a promotional rate generally has to last at least six months, and a late payment can end it early. Set the payment up as a recurring bill so the promo is never lost to a missed due date.
Sources
Frequently asked questions
Is a balance transfer worth it?
Compare the fee with the interest you avoid. In the example — $6,000 at 24.99% paying $300 a month, moved to 0% for 18 months with a 3% fee — the transfer saves $1,630.56. Staying put takes 2 years 3 months and $1,841.44 in interest.
How much should I pay each month on a balance transfer?
Enough to clear it before the intro APR ends. The calculator shows that figure: for $6,000 plus a $180 fee over 18 months at 0%, it's $343.33 a month. Paying $300 leaves some balance to roll onto the regular APR.
What happens when the 0% intro period ends?
Any balance left starts accruing interest at the card's regular APR. The calculator models that: it switches to the "APR after the intro period" in the month after the promotion ends.
How much is a balance transfer fee?
Commonly 3% to 5% of the amount moved, sometimes with a minimum such as $5 or $10. Enter the percentage from the offer; the fee is added to the new balance on day one.
Does a balance transfer hurt my credit score?
Applying for a new card usually means a hard inquiry and a new account, which can lower a score slightly for a while. Paying the balance down lowers your utilisation, which tends to help. Closing the old card can raise utilisation, so many people keep it open and unused.