Credit Card Debt Payoff Calculator and Payment Plan

A credit card debt payoff calculator estimates how many months it will take to repay a balance and how much interest you may pay, based on your balance, APR, and monthly payment. Enter those figures to see an estimated payoff time and total interest; the result assumes a fixed APR and the same payment every month.

Formula

The calculator estimates the number of level monthly payments needed to bring a balance to zero while interest accrues monthly. It uses:

• Monthly rate: r = APR / 1200, where APR is entered as a percentage per year.
• Months to payoff: n = ceil(round(−ln(1 − r × B / M) / ln(1 + r), 6)).
• Total paid: M × n.
• Total interest: M × n − B.

B is the starting balance in dollars, M is the fixed monthly payment in dollars, r is the monthly interest rate as a decimal, and n is the estimated number of monthly payments. The final payment is treated as the same amount as the other payments in the total, so the estimate can slightly overstate the amount actually needed when the balance is paid off partway through the last payment. The formula rounds the calculated payoff period up to a whole month.

Worked Example

Using the calculator’s defaults: balance B = $5,000, APR = 20%, and monthly payment M = $200.

1. Convert APR to a monthly rate: r = 20 / 1200 = 0.0166667, or about 1.66667% monthly.
2. Substitute into the payoff formula: n = ceil(round(−ln(1 − 0.0166667 × 5,000 / 200) / ln(1 + 0.0166667), 6)).
3. Evaluate the expression: n = ceil(41.36…) = 42 months.
4. Estimate total paid: $200 × 42 = $8,400.
5. Estimate interest: $8,400 − $5,000 = $3,400.

The results are 42 months to payoff, $3,400 in estimated interest, and $8,400 total paid.

Assumptions

• The APR stays fixed throughout repayment.
• Payments are made once each month, with interest applied monthly at APR divided by 12.
• Payments are level, made on schedule, and large enough to cover interest.
• Fees, new purchases, promotional-rate changes, penalty rates, taxes, and issuer-specific payment allocation are not included.

When to Use a Credit Card Payoff Calculator

Use the estimate to understand the relationship between a balance, its APR, and a planned monthly payment. It can help answer practical questions such as whether a payment is likely to reduce the balance, how repayment time changes when you pay more, or how much interest a steady-payment scenario could add. It is a planning calculation, not a statement of the amount due on an account.

For a useful estimate, check your latest statement for the balance and APR that apply to the debt you want to model. If a card has separate balances at different rates—for example, purchases and a promotional balance—one blended APR cannot accurately represent how the issuer calculates interest. Calculate each portion separately only if you know the rate and payment treatment for each; otherwise, treat this result as a rough illustration.

How to Read the Results and Compare Payments

The payoff-time result is rounded up to a whole number of months. The interest and total-paid figures multiply that month count by your entered payment, less the starting balance for the interest estimate. Actual last payments are often smaller than the regular payment because only the remaining balance and accrued interest need to be covered. Therefore, the displayed totals are a consistent estimate based on level payments, not a precise payoff quote.

To compare scenarios, keep the balance and APR unchanged and enter a different payment. A larger payment generally reduces the modeled payoff time and interest, provided it exceeds the interest accruing each month. For example, at the default balance and APR, monthly interest at the start is approximately $83.33 ($5,000 × 20% / 12). A payment must exceed the interest charged for the balance to begin declining under this simplified model. The precise amount of interest charged by a card issuer can vary with balance timing and account terms.

Common Problems and Limits

• Payment does not cover interest: If M is less than or equal to r × B, the logarithm has no valid payoff result. The balance will not be paid off under a fixed payment at that rate; paying only the accruing interest would not reduce principal.
• Minimum payments change: Many card payment calculations are not a constant dollar amount. If your payment falls as the balance falls, this calculator’s fixed-payment estimate will not match that schedule.
• New activity changes the balance: Purchases, cash advances, fees, and credits affect repayment. The model assumes no transactions after the starting balance.
• APR can vary: A variable rate or promotional rate expiration changes the interest path. This calculator does not model future rate changes.
• Daily interest and payment dates matter: The formula uses a monthly rate and regular monthly periods. Issuers may calculate interest using daily balances, so actual statement interest and payoff timing can differ.

Enter a payment in dollars per month, not an annual payment or a percentage of the balance. APR is a percentage, so enter 20 for 20%, not 0.20. Small differences can also result from rounding, because the calculator rounds the estimated number of months to a whole month and does not calculate a separate smaller final payment.

Frequently Asked Questions

How do I calculate how long it will take to pay off credit card debt?
Enter the balance, APR, and planned fixed monthly payment. The calculator applies a monthly interest rate of APR divided by 12 and estimates the number of monthly payments needed, rounded up to a whole month.

What monthly payment will pay off my credit card by a certain date?
This calculator does not solve for a payment from a target date. You can test different monthly payment amounts to see the estimated payoff month, but a changing APR, fees, or new charges can make the real schedule differ.

Why does the calculator say it cannot compute my payoff?
The payment may be too small to cover the estimated monthly interest on the starting balance. Check the APR and payment units, then test a payment greater than the starting monthly interest. If the actual account has fees or changing rates, consult its statement for the applicable details.

Does this include my credit card’s minimum payment formula?
No. It assumes the same dollar payment every month. A card issuer’s minimum-payment calculation may change over time and can include account-specific terms not represented here.

Is the result my exact payoff amount?
No. It is a mathematical estimate under the listed assumptions. The actual amount can change with daily balance calculations, payment dates, transactions, fees, APR changes, and a smaller final payment. The result is an estimate; the lender’s disclosure gives the exact figures.

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in bal | Credit card balance | $ | 5000 | 0 | 100000000
in apr | Interest rate (APR) | % | 20 | 0.01 | 100
in pay | Monthly payment | $ | 200 | 0.01 | 100000000
out mon | Months to payoff | months | ceil(round(-ln(1 - (apr / 1200) * bal / pay) / ln(1 + apr / 1200), 6)) | 0
out int | Total interest | $ | pay * mon - bal | 2
out tot | Total paid | $ | pay * mon | 2