About the Credit Card Interest Calculator
Credit card interest is easy to underestimate because it is built into a yearly rate and charged every day. At an APR of 22.9 percent, a balance of 4,000 costs about 75 in interest in a 30-day month, and that is added to what you owe. This calculator shows that monthly charge and the cost over a year. Then it compares two ways to pay: a fixed monthly payment of your choice, with the number of months it takes and the total interest, and the usual minimum payment of 1 percent of the balance plus interest, which can take many years. Seeing the two side by side makes it clear why paying more than the minimum matters.
Updated October 2026
How to use the Credit Card Interest Calculator
- 1Enter your card balance and APR.
- 2Enter the amount you plan to pay each month.
- 3Read the interest for a 30-day month and for a year.
- 4Compare your payment plan with paying only the minimum.
- 5Try larger payments to see the months and interest fall.
Worked example
You owe 4,000 at 22.9 percent. In a month, interest is about 75. If you pay 150 each month, you clear the debt in 38 months (just over three years) and pay about 1,643 in interest, 5,643 in total. If you pay only the minimum, which starts at about 116 and falls with the balance, it takes 210 months, or 17.5 years, and costs about 6,545 in interest, which is more than the original balance.
Ways to pay it down faster
- Pay as much as you can above the minimum.
- Target the card with the highest APR first.
- Use windfalls such as tax refunds.
- Set up an automatic payment above the minimum.
- Stop adding new purchases to the balance.
Understanding APR
APR is a yearly rate, but interest is added daily or monthly, so the effective cost is a little higher than the nominal figure. A card with 22.9 percent APR compounding daily has an effective annual rate of about 25.7 percent if you never pay. That is why balances grow quickly when they are left alone.
Related tools
The Credit Card Payoff Calculator builds a full plan, the Debt Payoff Calculator handles several debts, the Credit Utilization Calculator shows how balances affect your score and the APR Calculator compares offers.
Features
- Interest for a month and a year
- Payoff time at a fixed payment
- Minimum-payment scenario
- Total interest in each case
- Warning if the payment doesn't cover interest
- Any currency
Frequently asked questions
How is credit card interest calculated?
Most cards charge a daily rate, which is the APR divided by 365, on the average daily balance. For a month, interest is roughly the balance times the APR divided by 12. On 4,000 at 22.9 percent that is about 76, or 75.29 using daily interest over 30 days.
What is a minimum payment?
The smallest amount you must pay to keep the account in good standing. It is often the larger of a flat amount, such as 25, or 1 to 3 percent of the balance plus interest and fees. It keeps the debt alive for a long time.
How long does it take to pay off a card?
It depends on the balance, rate and payment. Paying 150 a month on 4,000 at 22.9 percent takes 38 months and costs about 1,643 in interest. Paying only the minimum would take about 17 years and cost over 6,500 in interest.
Does paying in full avoid interest?
Usually, yes. If you pay the full statement balance by the due date, most cards charge no interest on purchases during the grace period. Cash advances and balance carried over from before are different.
How can I reduce my interest?
Pay more than the minimum, move the balance to a card with a lower or 0 percent rate for a limited time, ask your issuer for a lower rate or use a personal loan to refinance. Avoid new purchases on a card with a balance.
Why does my statement show a different amount?
Statements use your exact daily balances, payment dates and any fees. New purchases, payments during the month and different month lengths all change the figure. This tool gives a close estimate.