Credit Card Debt Payoff Calculator and Payment Plan

This credit card debt payoff calculator estimates how many monthly payments it will take to clear a balance and how much interest you will pay. Enter your balance, APR, and fixed monthly payment to see the estimated payoff time and total interest.

Formula

The calculator finds the number of equal monthly payments needed to reduce the balance to zero, then estimates total paid and interest. It uses:

• Monthly rate: r = APR / 1200, where APR is entered as a percentage per year.
• Estimated months: n = ceil(round(-ln(1 – r × B / M) / ln(1 + r), 6)).
• Total paid: T = M × n.
• Estimated interest: I = T − 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 number of months. The calculator rounds the computed payoff period up to a whole month, because a partial final month is represented as a final full payment in this simplified estimate. Total paid assumes the same payment each month, including the last one; actual final payment may be smaller.

Worked Example

Using the defaults—balance $5,000, APR 20%, and payment $200 per month:

1. Monthly rate: 20 / 1200 = 0.0166667.
2. Unrounded payment count: −ln(1 − 0.0166667 × 5,000 / 200) / ln(1.0166667) ≈ 32.61 months.
3. Round up to a whole month: 33 months.
4. Estimated total paid: 33 × $200 = $6,600.
5. Estimated interest: $6,600 − $5,000 = $1,600.

This example uses the same calculation as the block. Because the last payment is treated as $200, the estimated total can exceed what would be due if the remaining balance were paid exactly at the end.

Assumptions

• The APR stays fixed throughout the payoff period.
• Payments are made monthly, at the end of each monthly period.
• Interest compounds monthly using APR divided by 12.
• The payment amount stays constant; no new purchases, cash advances, credits, or missed payments occur.
• Fees, promotional-rate changes, penalty rates, taxes, and other card-specific terms are not included.

How to Use the Estimate

Use a current statement balance and the APR that applies to that balance. If a card has separate rates for purchases, transfers, or cash advances, this single-rate calculator cannot model those balances separately. The payment should be the amount you intend to send each month, not a one-time payment. Entering a payment that does not cover the month’s interest produces an invalid calculation: the balance would not decline under the model.

The result is a planning estimate, not a payoff quote. Card issuers may calculate interest using daily balances, and statement cycles do not always line up with a neat monthly period. Payment posting dates and changing balances can therefore cause actual interest and timing to differ. Check your card statement or issuer for the balance and rate that apply, and use a payoff amount supplied for a specific date when you need an exact figure.

Reading the Results and Common Mistakes

“Months to pay off” is the number of monthly periods in the simplified model. Divide by 12 for a rough year-and-month interpretation; for example, 33 months is 2 years and 9 months. “Estimated interest” is total modeled payments minus the starting balance. It is not a separate fee charged all at once.

• Using the wrong APR: A card can have different rates for different transaction types, or a rate that changes. Use the rate applicable to the balance being estimated.
• Entering a minimum payment as a fixed payment: Minimum payments can change as the balance changes. This calculator assumes a constant amount, so it does not reproduce a declining-payment schedule.
• Ignoring new charges: Purchases added during payoff change both the balance and interest. The estimate assumes no new borrowing.
• Confusing APR with monthly rate: Enter APR as a yearly percentage, such as 20, not 1.6667. The formula converts it to a monthly rate.
• Overreading rounded results: The payoff period is rounded up to whole months. The last real payment may be less than the regular monthly amount.

Other Ways to Estimate Repayment

A fixed-payment estimate is useful when you can model a steady payment, but it is not the only repayment pattern. Paying a fixed amount above a changing minimum generally produces a different schedule than paying only the minimum. A full amortization schedule can show the balance and interest month by month; a multi-card debt calculator can account for several balances and payments, though it needs each card’s balance, APR, and payment allocation rules.

For a more detailed estimate, gather each card’s current balance, applicable APR, payment amount, and any known promotional-rate end date or fee. Model balances separately when rates differ rather than blending them into one APR. If terms change, recalculate from the new balance and rate instead of treating the original estimate as guaranteed.

Frequently Asked Questions

How do I calculate how long it will take to pay off a credit card?
Use the current balance, APR, and a steady monthly payment in the payoff formula. The calculator estimates the number of whole monthly periods, assuming the rate and payment do not change.

What monthly payment should I enter?
Enter the fixed amount you want the estimate to model. If you are comparing possible payment amounts, calculate each one separately; the result does not determine what payment is suitable for your circumstances.

Why does the calculator say it cannot compute?
The payment may be too small to cover the interest calculated for a month. If the payment does not reduce the balance, the formula cannot produce a finite payoff period. Check the APR, balance, and payment entries.

Does this include new purchases or late fees?
No. It assumes the balance only declines through the modeled payments and excludes new transactions and fees. Those additions can increase the amount owed and extend repayment.

Is the final payment exactly the monthly payment entered?
Not necessarily. This estimate rounds the payoff time up to a whole month and multiplies that count by the regular payment. A real final payment may be smaller, and actual interest depends on the account’s terms and payment timing.

This result is an estimate for educational purposes, and the card issuer’s disclosure and payoff information provide the exact figures.

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