Balance Transfer Calculator projects how moving a credit card balance to a given promotional rate affects total interest, fees, and the months needed to pay off the debt in full
Balance Transfer Calculator: Compare Payoff Costs Between Two Credit Cards
This balance transfer calculator projects the interest, fees, and payoff timeline of moving a revolving credit card balance to a new card with a promotional annual percentage rate (APR), then compares that outcome against keeping the debt on the current card. It’s used by cardholders carrying an ongoing balance who want to see whether a transfer offer’s fee is outweighed by the interest it would save before applying for a new card.
Entering Your Current Balance, Rate, and the New Card’s Promotional Terms
Inputs are the current balance, the current card’s nominal APR, a planned fixed monthly payment, the new card’s transfer fee (%), its promotional APR and duration in months, and the rate that applies after the promotion ends. The calculator assumes monthly compounding — the nominal APR is divided by 12 to get a monthly periodic rate — and does not perform currency conversion; selecting INR, EUR, or GBP only changes the displayed symbol.
How the Interest Savings and Payoff Timeline Are Calculated
Both scenarios are run through the same month-by-month amortization method, the standard approach used in financial and actuarial texts for a fixed payment against a declining balance. For a given month, interest owed is
$$I_m = B_m \times \frac{r}{12}$$
where $B_m$ is the balance at the start of the month and $r$ is the nominal annual rate as a decimal. The payment first covers $I_m$, and the remainder reduces principal:
$$B_{m+1} = B_m – (Pmt – I_m)$$
On the new card, the transfer fee is added to the starting balance rather than paid separately, so $B_0 = B_{transfer} \times (1 + fee)$, and the rate used in the formula above switches from the promotional APR to the post-promo APR once the promotional month count is reached.
Net savings is the difference between total amount paid on the current card and total amount paid on the new card (principal, interest, and fee combined). A common input mistake is entering a monthly rate where the calculator expects the nominal annual APR printed on the card statement, which understates interest by roughly a factor of 12.
Valid inputs are a positive balance, a payment greater than zero, and non-negative rates and fees; a promotional duration of 0 is valid and simply applies the post-promo rate from month one, effectively modeling a card with no introductory offer.
If the monthly payment doesn’t exceed the interest charge on either card, that balance cannot amortize down to zero and the calculator flags the scenario rather than returning a payoff date. Because the amortization loop is bounded at 1,200 months (100 years) to avoid an open-ended calculation, scenarios that would genuinely take longer than that to pay off will show incomplete results.
One interaction worth knowing before relying on the output: this calculator applies the post-promo rate to whatever balance remains once the promotional period ends — it does not model deferred-interest promotions, a structure some real balance transfer and store-card offers use where, if the balance isn’t paid in full by the end of the promo period, interest is charged retroactively on the entire original amount rather than just the remaining balance going forward. Check your card’s specific terms for that clause.
Because every result here is a projection built from the rate and payment you enter, treat the output as an estimate for comparing offers rather than as personalized financial or credit advice.
Interest Cost Comparison: Current Card vs. a Transferred Balance
Typical Balance Transfer Fees and the Current Average Credit Card APR
These reference figures are U.S.-specific; balance transfer fee structures and disclosure rules vary by country, so cardholders outside the U.S. should confirm terms with their issuer rather than apply these figures directly.
| Reference value | Figure | Source and date |
|---|---|---|
| Typical balance transfer fee | 3%–5% of the transferred balance (often a $5–$10 minimum instead, whichever is greater) | Market convention reported by consumer-finance publishers including Bankrate and Experian; not a statutory rate, and issuers set their own terms |
| Average APR, accounts assessed interest | 22.15% | Federal Reserve G.19 Consumer Credit report, Q2 2026 |
| Federal cap on card APR | None | Credit CARD Act of 2009 restricts when and how issuers can raise rates but sets no maximum APR; some state laws impose their own limits |
Common Questions About Comparing Balance Transfer Offers
Does the currency selector convert my balance into a different currency?
No. Switching between USD, INR, EUR, GBP, and the other supported currencies only changes the displayed symbol. The amortization math is identical regardless of which currency is selected; there’s no live exchange-rate conversion involved.
Does the balance transfer fee get paid upfront or added to my new balance?
This calculator always adds the fee to the new card’s opening balance rather than treating it as a separate out-of-pocket cost. That means interest can accrue on the fee itself once the payoff period begins, particularly if the promotional APR is above 0%.
Why does the calculator say my payment is insufficient?
That message appears when the monthly payment entered doesn’t cover the interest charged that month on either card. A balance can’t amortize toward zero if the payment never exceeds the interest accruing on it, so no payoff timeline can be projected.
What’s the longest payoff period the calculator can project?
The underlying calculation runs for up to 1,200 months, or 100 years. Realistic balance transfer scenarios finish well before that, but a very low payment relative to the balance can produce an incomplete result rather than a finished payoff date.
Does this calculator account for deferred-interest promotions?
No. It applies the post-promo APR only to the balance remaining once the intro period ends. Some real-world promotions instead charge interest retroactively on the full original amount if it isn’t paid off in time — check your specific card’s terms for that distinction.
Is the 22.15% average APR figure the rate I should use for my current card?
No, that figure is a nationwide U.S. average across accounts assessed interest as of Q2 2026, per the Federal Reserve. Enter the actual APR printed on your card statement for an accurate comparison.