Credit Card Balance Transfer Payoff Calculator

This calculator estimates how many months it will take to pay off a credit card balance after a balance transfer, using the transferred balance, transfer fee, APR, and monthly payment. Enter the figures shown in your card offer to see the estimated payoff time and total paid; it does not determine whether a transfer is suitable for you.

Formula

The estimate first adds the transfer fee to the balance, then calculates how many equal monthly payments are needed to repay that amount at the monthly interest rate. The payment is assumed to remain constant, with interest accruing monthly.

• Starting balance, B = balance transferred × (1 + fee percentage ÷ 100), in dollars.
• Monthly rate, r = APR ÷ 1200, as a decimal rate per month.
• Months, n = round up [−ln(1 − rB ÷ payment) ÷ ln(1 + r)].
• Total paid = monthly payment × estimated months, in dollars.
• Interest and fee estimate = total paid − original transferred balance, in dollars.

Here, APR is the annual percentage rate entered as a percentage, ln is the natural logarithm, and rounding months up means the estimate counts a final partial month as a whole payment period. The calculation requires the payment to exceed the interest charged in the first month; otherwise the balance will not shrink under this fixed-payment model.

Worked Example

Using the calculator’s defaults: a $5,000 transferred balance, 3% fee, 18% APR, and $250 monthly payment.

1. Fee-inclusive starting balance: $5,000 × (1 + 3 ÷ 100) = $5,150.
2. Monthly rate: 18 ÷ 1200 = 0.015, or 1.5% per month.
3. Months: round up [−ln(1 − 0.015 × $5,150 ÷ $250) ÷ ln(1.015)] = round up [−ln(0.691) ÷ ln(1.015)] = round up (24.89) = 25 months.
4. Total paid under the estimate: $250 × 25 = $6,250.00.
5. Estimated interest and fee above the original balance: $6,250 − $5,000 = $1,250.00.

The final payment in practice may be smaller than $250 because the remaining balance may not equal a full payment. The calculator uses the same payment for every counted month, so its total is a simplified estimate rather than a statement-level payoff quote.

Assumptions

• The APR is fixed throughout the modeled payoff period.
• Payments are made once per month after interest accrues for that month.
• Interest compounds monthly at APR ÷ 12.
• The transfer fee is added to the transferred balance at the outset.
• No new purchases, late payments, penalty rates, annual fees, or other charges are included.

How to Read the Estimate

The first result is the estimated number of months until payoff. The next result multiplies that period by the payment you entered. “Interest and fee paid” subtracts the original transferred balance from that total, so it combines the modeled interest with the transfer fee rather than separating them.

For example, if the APR input reflects a promotional rate that ends before the estimate’s payoff date, the calculator’s fixed-rate assumption will not describe the whole period. A changed rate, changing payment, or fee charged differently can also make the actual total and payoff date differ. Use the card agreement or offer disclosure for the actual introductory period, post-promotion APR, fee, and payment terms.

How to Use It and Common Mistakes

Enter the amount you plan to transfer, the fee percentage stated in the offer, the APR that applies to the months you are estimating, and a monthly payment. If the fee is a flat dollar amount rather than a percentage, convert it to a percentage of the transferred balance for this calculator: fee dollars ÷ balance dollars × 100. For instance, a $150 fee on a $5,000 transfer is 3%.

• Do not omit the fee: a fee can increase the balance that accrues interest, even when it is not paid separately.
• Check which APR applies: an introductory APR and a later APR are different assumptions. One fixed-rate result cannot model a change date.
• Use the payment you can actually make: this is a mathematical input, not a required payment or a recommendation.
• Avoid new charges in the comparison: purchases on the same card may have different terms and are not represented here.
• Remember the rounding: payoff months round upward; actual card statements calculate interest and payments under the account’s terms.

If the entered payment is no greater than the first month’s interest, the formula cannot produce a finite payoff period. This is not a software error: under the assumed fixed payment and rate, the balance would not be paid down. A very small payment above that threshold can also produce a long payoff estimate.

What a Balance Transfer Does—and Does Not Do

A balance transfer moves debt from one credit account to another. It changes where the balance is owed; it does not erase the debt. A fee may apply, and the interest charged depends on the terms that apply to the transferred balance. The amount you can transfer, timing, promotional period, and treatment of purchases are account-specific details that must be checked in the offer and card agreement.

A common misconception is that a promotional or low introductory rate makes the entire transfer cost-free. Even if a low rate applies for a period, a transfer fee can still add to the balance. Also, if repayment takes longer than that period, interest may accrue at a different APR afterward. This calculator cannot combine two rates over time; calculate separate periods or use the card issuer’s payoff information when the rate changes.

Frequently Asked Questions

Does a balance transfer pay off my credit card debt?
A transfer moves a balance to another account; it does not pay off the debt by itself. You still owe the transferred balance and any applicable fee, and must make payments under the new account’s terms.

How do I calculate the payoff time after a balance transfer?
Add any percentage-based transfer fee to the balance, convert APR to a monthly rate by dividing by 12 and then by 100, and apply the fixed-payment payoff formula. This calculator performs that estimate when the payment exceeds monthly interest.

Does this calculator include the balance transfer fee?
Yes. It adds the entered percentage fee to the transferred balance before estimating interest. It assumes the fee is charged once at the start and does not account for a separate flat fee unless converted to a percentage.

What if my promotional APR expires before I pay off the balance?
The calculator assumes one fixed APR and cannot model the rate change. Check the promotional end date and subsequent APR in the offer, then use figures that reflect the period being estimated or obtain a payoff calculation based on both periods.

Why does it say the balance cannot be paid off?
If the monthly payment does not exceed the first month’s interest on the fee-inclusive balance, the assumed balance will not decline. A different payment or rate changes the arithmetic, but the calculator does not prescribe either.

This is estimate arithmetic for education, not financial advice; the card issuer’s disclosure and account terms provide the exact figures.

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in bal | Balance transferred | $ | 5000 | 0 | 100000000
in fee | Transfer fee | % | 3 | 0 | 100
in apr | Interest rate (APR) | % | 18 | 0.01 | 100
in pay | Monthly payment | $ | 250 | 0.01 | 100000000
out mon | Months to payoff | months | ceil(round(-ln(1 - (apr / 1200) * (bal * (1 + fee / 100)) / pay) / ln(1 + apr / 1200), 6)) | 0
out tot | Total paid | $ | pay * mon | 2
out cost | Interest and fee paid | $ | tot - bal | 2