The one rule: fix your payment
Card minimums decline as your balance declines — a design that stretches payoff into decades. Freezing your payment at any fixed number converts the card into a normal amortizing loan with a real end date. That's the entire trick, and the ladder above prices each step of aggression. For the mechanics of daily compounding and the grace period, read how credit card interest works; for multiple cards, sequence them with the debt snowball calculator.
How this calculator works
The model compounds monthly at APR ÷ 12 and answers the question in either direction — payment to time, or target date to required payment:
Monthly interest
interest = balance × APR ÷ 12
Fixed-payment payoff
n = −ln(1 − r·P ÷ M) ÷ ln(1 + r)
- P — current card balance
- r — monthly rate — APR ÷ 12
- M — your fixed monthly payment
Card issuers actually accrue daily, which lands within a few dollars of monthly compounding on typical balances — the timeline is what matters. If your payment doesn’t beat the monthly interest, the tool says so plainly instead of showing a date.
Worked example
An $8,000 card balance at 22.99% APR, paying a fixed $250/month versus a fixed $350/month.
| First month’s interest alone | $153.27 |
|---|---|
| Payoff time at $250/mo | 4 yr 3 mo (51 months) |
| Total interest at $250/mo | $4,509 |
| Payoff time at $350/mo | 31 months |
| Interest saved at $350/mo | $1,883 |
At $250/month, $153 of the very first payment is pure interest — only $97 touches the balance, which is why payoff drags to over four years and costs $4,509. Raising the fixed payment to $350 cuts the timeline by 20 months and saves $1,883. The key is holding the payment fixed: card minimums shrink as the balance falls, which is the trap. See why minimum payments keep you in debt.
Frequently asked questions
How long will it take to pay off my credit card?
Divide-and-guess doesn’t work because interest compounds while you pay. Enter your balance, APR, and a fixed monthly payment above: a $5,000 balance at 24% with $200/month takes about 2 years 9 months and roughly $1,600 of interest. The ladder table shows how +$50 or +$100 changes that.
What payment do I need to be debt-free by a target date?
Switch the calculator to goal mode and enter the months: it computes the exact fixed payment using the same amortization math as a loan. Paying a FIXED amount — rather than the card’s declining minimum — is the single biggest accelerator.
Why does paying only the minimum take decades?
Minimums are typically interest + 1% of the balance and shrink as the balance shrinks, stretching the timeline enormously. Your statement’s “minimum payment warning” box shows the issuer’s own projection. See our guide on the minimum-payment trap for the mechanics.
Should I use a balance transfer instead?
A 0% transfer (typical fee 3–5%) stops interest for 12–21 months — mathematically strong if you can clear the balance within the promo window. Compute the payment needed here with goal mode set to the promo length, add the fee, and compare.
Which card should I pay first if I have several?
Highest APR first (avalanche) minimizes interest; smallest balance first (snowball) builds momentum. Our debt snowball calculator compares both on your actual cards, with payoff dates.
Does carrying a small balance help my credit score?
No — that’s a persistent myth. Utilization is reported whether or not you pay interest; paying in full builds the same history for free.
Related calculators
- Debt Snowball Calculator — Compare the snowball and avalanche payoff methods side by side across all your debts.
- Debt Consolidation Calculator — Your debts vs. a real loan offer at the same monthly budget — fees counted, longer-term tricks exposed.
- Loan Payoff Calculator — See how extra payments shorten your loan and how much interest you save.
- Personal Loan Calculator — Payment, total interest, and full schedule for any personal loan — plus early-payoff savings.
Disclaimer: Educational purposes only — not financial advice. Card issuers’ exact daily-accrual results differ slightly from monthly models. See our Terms of Use.