Use this Balance Transfer Calculator to compare transfer fees, promo and post-promo APRs, payoff time, monthly payment, interest, and estimated savings.
Balance Transfer Formula
A balance transfer begins with the amount moved plus any transfer fee that is added to the new card. If the fee is paid separately, it is counted as an up-front cost rather than part of the new balance.
BT = B * (1 + f)
To clear the transferred balance during a promotional period, the required monthly payment is the standard amortizing payment:
P = BT * r / (1 - (1 + r)^(-n))
When the promotional APR is 0%, the formula simplifies to P = BT / n.
Variables:
- BT is the starting transferred balance
- B is the balance moved from the old card
- f is the transfer-fee percentage as a decimal
- P is the payment required each month
- r is the promotional monthly rate
- n is the number of promotional months
Comparison mode simulates both choices until payoff. The current-card path uses the current APR, while the transfer path uses the promotional APR for the entered number of months and the post-promotional APR afterward. Estimated savings equal the current-card interest minus transfer interest and the transfer fee.
Payment Needed During a 0% Promotion
This table assumes a $5,000 balance, a 3% transfer fee added to the new balance, and a 0% promotional APR.
| Promotional period | Starting transferred balance | Payment to finish in time |
|---|---|---|
| 12 months | $5,150.00 | $429.17 |
| 15 months | $5,150.00 | $343.33 |
| 18 months | $5,150.00 | $286.11 |
| 21 months | $5,150.00 | $245.24 |
Example Problems
Example 1: Payment needed to finish during the promotion.
You transfer $8,500 with a 3% fee to an 18-month 0% offer. The fee is 8500 * 0.03 = $255, so the new balance is $8,755. Dividing by 18 gives a required payment of about $486.39 per month.
Example 2: Compare total borrowing cost.
A $300 monthly payment on $8,500 at 24.99% APR takes about 44 months and creates roughly $4,480 of interest. Moving the balance to an 18-month 0% offer with a 3% fee and the same post-promo APR pays off in about 31 months under the same payment. Estimated transfer interest plus the fee is about $759, a savings of roughly $3,720 under these assumptions.
Frequently Asked Questions
Does a 0% balance transfer have no cost?
Not necessarily. Many offers charge a one-time transfer fee, and any balance remaining after the promotion can begin accruing interest at the regular rate. Late payments may also affect promotional terms.
Should the transfer fee be added to the balance or paid up front?
It depends on the offer. Many issuers add it to the new balance, but some arrangements collect it separately. Choose the setting that matches the disclosure because it changes both the starting balance and the cash paid up front.
Can new purchases change the result?
Yes. Purchases may have a different APR, may not receive a grace period while a transferred balance is carried, and increase the amount that must be repaid. This calculator assumes no new charges.
