Quick answer
This calculator simulates paying a credit card balance the minimum-payment way, so you can see what 'minimum' really costs. A $5,800 balance at 24.99% APR with a typical minimum of interest plus 1% of the balance (with a $25 floor) takes 251 months — nearly 21 years — and $10,944 of interest. The same balance at a fixed $200 a month clears in 45 months with $3,187 of interest.
How the Credit Card Calculator works, step by step
Enter the balance, the APR and how you intend to pay: minimum only, a percentage of the balance, or a fixed monthly amount. The calculator steps through the balance month by month, charging interest at APR ÷ 12 and applying your payment, exactly as the card statement does, and compares all three modes side by side.
Minimum payments are designed to shrink. A typical formula is the month's interest plus 1% of the balance (or 2% to 4% of the balance, varying by issuer), with a floor around $25. Early on, most of the payment is interest: month one on the example balance charges $120.79 of interest against a payment of about $179.
The fixed-payment comparison is the point of the tool. Holding a fixed payment of $200 — only about $21 more than the first month's minimum — and never letting it fall turns a 21-year debt into a three-and-three-quarter-year one on this balance, because every dollar that interest stops claiming goes straight to principal.
A percentage-of-balance payment can be worse than the minimum, which surprises people. Paying 3% of the balance each month on the example takes 268 months and $11,877 of interest — longer and costlier than the minimum formula — because 3% of a shrinking balance falls faster than interest plus 1% does in the early years. Any payment that shrinks with the balance has the same flaw.
Your own statement already carries this warning. Since the CARD Act of 2009, Regulation Z requires every card statement to show a minimum payment warning: how long the balance would take and what it would cost at minimums only, plus the monthly payment that would clear it in 36 months. On the example balance that 36-month payment is about $231, with $2,501 of interest.
The formula
Each month: interest = balance × APR ÷ 12. Minimum payment = max(interest + 1% of balance, $25) for the modelled issuer formula. Percentage mode pays max(balance × %, $25). Fixed mode pays a constant amount. Balance falls by (payment − interest) until it reaches zero.
Worked example — try it on the calculator above
Worked example: $5,800 at 24.99% APR, minimum payments only
Month one: interest $120.79, minimum payment $178.79 (interest plus 1% of the balance), so principal falls by just $58. The balance halves only after about 6 years. Final payment arrives in month 251, and total interest is $10,944 — you repay about $16,744 for $5,800 of spending. A fixed $200 a month clears the same balance in 45 months with $3,187 of interest, saving $7,757 and more than 17 years. Federal rules require your statement to print this comparison; this calculator lets you run it for any payment you choose, before you choose it.
Frequently Asked Questions
How is credit card interest actually calculated?
Most issuers use the average daily balance method: the daily rate (APR ÷ 365) applies to each day's balance, including new purchases once any grace period is lost. Pay the full statement balance by the due date and purchases incur no interest — the grace period, at least 21 days under Regulation Z. Carry any balance and it disappears, so new purchases accrue interest from the day they post.
What APR is typical for a credit card?
High. Federal Reserve G.19 data put the average rate on accounts assessed interest at 22.36% in the third quarter of 2026 (21.19% across all accounts, including those paid in full). Store cards run higher still. Against those rates, even a strong savings account yield is irrelevant: paying a 22% APR is a guaranteed 22% return on the money used to clear it.
Will a fixed payment hurt my credit score compared with minimums?
No — paying more than the minimum is positive in every respect. Scores care about on-time payment (any amount at or above the minimum satisfies it) and utilisation, the share of your limit in use. Bigger payments cut utilisation faster. Keep reported utilisation under about 30%, and lower is better.
I cannot afford more than the minimum. What are the options?
In order: ask the issuer for a hardship plan or a rate reduction (issuers grant these more often than borrowers expect); consider a 0% balance transfer if the fee buys enough interest-free months to change the outcome; or speak to a non-profit credit counsellor about a debt management plan, which typically cuts card APRs to single digits in exchange for closing the cards. Avoid debt settlement companies charging upfront fees.
Estimates, not advice. This calculator provides educational estimates based on the inputs you enter and the assumptions shown on this page. It is not financial, tax or investment advice, and it cannot see your full situation. Verify important figures against official sources, and consider a qualified professional for decisions about your own money. See our Disclaimer and Methodology.