About the Credit Card Calculator
A credit card calculator shows how long a balance takes to clear at a given monthly payment, and how much interest that costs. Card debt is the most expensive borrowing most households encounter, and the arithmetic of minimum payments is genuinely alarming.
The formula
n = −log(1 − (B · r) / PMT) / log(1 + r)B is the balance, r the monthly rate (APR divided by 12), and PMT the monthly payment. If the payment is below the monthly interest, the balance never clears.
How to use this calculator
- 1Enter your Current Balance ($). The field starts at
5000, which you can overwrite. - 2Enter your Annual Interest Rate (APR %). The field starts at
22.99, which you can overwrite. - 3Enter your Monthly Payment ($). The field starts at
200, which you can overwrite. - 4Read the result straight away — it recalculates as you type, so there is no button to press. Use Share to copy a link that reopens the page with your exact numbers filled in.
Worked example
| Input | Value |
|---|---|
| Current Balance ($) | 5000 |
| Annual Interest Rate (APR %) | 22.99 |
| Monthly Payment ($) | 200 |
Result
Payoff Time: 2 yr 11 mo
Total Paid: $6870.64
Total Interest: $1870.64
Monthly Interest: $95.79
Those are the values the page loads with, so you can reproduce this result yourself and then change one field at a time to see what drives the outcome.
Understanding your result
Minimum payments are structured to maximise interest, typically at 1 to 3 percent of the balance or a small floor amount. Paying the minimum on a 5,000 dollar balance at 23 percent APR takes well over fifteen years and costs more in interest than the original debt. The minimum is designed to keep you paying, not to clear the balance.
Because card interest compounds daily on most accounts, small increases in payment have disproportionate effects. Raising the payment from 100 to 200 dollars a month on a 5,000 dollar balance cuts the payoff from decades to under three years — the extra money goes entirely to principal, and every dollar of principal removed stops accruing interest permanently.
Things worth knowing
- Always pay more than the minimum. Even a small increase dramatically shortens the payoff.
- A 0 percent balance transfer can pause interest, but check the transfer fee of typically 3 to 5 percent and clear the balance before the promotion ends.
- Paying the statement balance in full every month means paying no interest at all.
- The avalanche method — highest rate first — minimises total interest across multiple cards.
- Cash advances usually carry a higher rate with no grace period, so interest starts immediately.
Frequently asked questions
How long does it take to pay off a credit card at the minimum?+
Frequently 15 to 25 years on a typical balance, with total interest exceeding the original debt. Minimum payments are calculated to keep the account profitable, not to clear it.
How is credit card interest calculated?+
Usually on the average daily balance, compounded daily. Dividing the APR by 365 gives the daily rate, which is applied to each day's balance and added at the end of the cycle.
Is a balance transfer worth it?+
Often, if you clear the balance within the promotional period. Weigh the 3 to 5 percent transfer fee against the interest saved, and note that the rate after the promotion is usually high.
Does carrying a balance improve my credit score?+
No — this is a persistent myth. Paying in full each month builds credit just as effectively and costs nothing. High utilisation actually lowers your score.