Why does the minimum payment change every month?

Most cards calculate the minimum as a percentage of the current balance plus interest — as the balance shrinks, so does that percentage-based portion, which is exactly why minimum-only payoffs stretch out for so long.

Is 1% a typical minimum payment percentage?

It's a commonly cited figure, but minimum payment formulas vary by issuer — some use 1%, others 2-4%, often combined with interest and a flat-dollar floor. Check your own card's cardholder agreement for the actual formula.

How much does paying more than the minimum actually save?

It varies by your specific balance, APR, and payment amount, but on a high-APR card even a modest increase can cut years off the payoff time and save substantial interest — this tool computes your exact numbers rather than a rule of thumb.

Does this include any fees, like a balance transfer fee?

No — this models interest accrual and payments only. If you're considering a balance transfer, add its fee (commonly 3-5% of the transferred balance) to your comparison separately.

What if my APR changes over time (e.g. a promotional rate expires)?

This tool assumes a constant APR for the full simulation — if you have a promotional rate that will later increase, rerun the numbers with the higher rate to see the more realistic long-term picture.

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Finance

Credit Card Interest Calculator

How long minimum payments take to clear a balance, and interest saved by paying more.

🔒 Runs entirely in your browser — nothing here is ever uploaded

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Last reviewed 2026-08-30

About the Credit Card Interest Calculator

Simulates how long it takes to pay off a credit card balance under minimum payments alone versus a fixed payment you choose, month by month, showing total interest paid and how much time and interest a bigger payment actually saves.

100% Free Runs in Your Browser No Sign-Up Required

How to use it

Enter your current balance and APR.
Enter your card's minimum payment formula — typically a % of balance plus that month's interest, with a flat-dollar floor.
Optionally enter a fixed payment you're considering instead.
Read the time to pay off and total interest under each scenario.

Formula

Each month: interest = balance × (APR ÷ 12 ÷ 100). Minimum payment = max(flat-dollar floor, balance × minimum % + that month's interest). New balance = balance + interest − payment. The simulation repeats month by month until the balance reaches zero (or is capped at 50 years, flagging a payment that never actually pays down the balance).

Worked example

A $5,000 balance at 22% APR, minimum payment of 1% of balance plus interest (floored at $25): paying only the minimum takes years and costs substantial interest; a fixed $200/month payment instead pays it off dramatically faster with far less total interest — the exact figures depend on your specific inputs.

Interpreting your result

Minimum-payment formulas vary by issuer — this models the common 'percent of balance plus that month's interest, or a flat-dollar floor, whichever is greater' structure, but check your own card's actual terms. Because most minimum payments shrink as the balance shrinks (a smaller % of a smaller balance), paying only the minimum can take many years and cost more in interest than the original balance itself — this simulation makes that visible month by month rather than with a single simplified formula.

Recommendations

• If minimum payments show 'never pays off,' it means the minimum-payment formula's percentage portion doesn't grow fast enough to outpace the APR at low balances — even a small fixed payment increase can turn this around.
• The gap between minimum-only and a fixed payment tends to be largest on high-APR cards — credit card APRs are typically far higher than mortgage or auto loan rates, so extra payments here often have an outsized impact.
• If you're carrying a high-interest balance, compare this against a balance-transfer offer or the Debt Payoff Calculator's snowball/avalanche approach for tackling multiple debts.

Frequently asked questions

If the minimum payment (a percent of balance plus interest) doesn't exceed that month's accrued interest, the balance never actually shrinks — this typically happens when the percentage is too low relative to a high APR.