Credit Card Interest & Payoff Calculators
Sixteen free calculators to help you estimate what your credit card costs — and how to pay it off faster. Built by Ali Ahmad, with every calculator checked against hand-worked examples and an automated test suite, and every rule linked to its CFPB, Federal Reserve, or Regulation Z source.
A credit card interest calculator shows how much of your payment goes to interest versus principal, based on your balance, APR, and payment amount. Many issuers apply a daily periodic rate (your APR ÷ 365) to your average daily balance; most of our calculators use a simplified monthly model (APR ÷ 12), so your statement may differ. Use the Credit Card Interest Calculator below to see your estimated interest and payoff results.
All 16 Calculators
Credit Card Interest Calculator
Estimate how much of your next payment goes to interest versus principal — and what your balance could cost you over time.
Open calculator →Credit Card Payoff Calculator
Enter your balance, APR, and monthly payment to see your estimated payoff date and total interest cost — then test how extra payments shorten it.
Open calculator →Credit Card Minimum Payment Calculator
Estimate your minimum payment under common formulas — and what paying only the minimum every month could cost.
Open calculator →Credit Card Balance Transfer Calculator
Compare what you'd pay by staying put versus transferring your balance — fees included — to see your real net savings.
Open calculator →Multi-Card Debt Payoff Calculator (Snowball vs. Avalanche)
Add every card you're carrying a balance on and see, side by side, which order of payoff — smallest balance first or highest APR first — saves you more.
Open calculator →Credit Card APR Calculator
Turn an abstract percentage into real numbers: see what your APR costs you per month and per year on your actual balance.
Open calculator →Credit Card Daily Interest Calculator
See the daily periodic rate typically derived from your APR, and how many dollars that adds up to per day and per billing cycle.
Open calculator →Extra Payment Savings Calculator
Add a fixed extra amount to your monthly payment and see an estimate of how many months and how many dollars in interest it could save you.
Open calculator →0% Intro APR Calculator
Find the monthly payment required to clear your balance before the promotional 0% period ends, and see the cost if you fall short.
Open calculator →Deferred Interest Calculator
For "no interest if paid in full" store card and retail financing offers: see the interest building up in the background, the payment that avoids it, and what you owe if you miss the deadline.
Open calculator →Credit Utilization Calculator
Your utilization ratio is one of the biggest factors in your credit score after payment history. See yours instantly, per card and overall.
Open calculator →Debt Consolidation vs. Balance Transfer Calculator
Two very different ways to tackle the same balance — compare total cost side by side before you decide.
Open calculator →Cash Advance Calculator
See the full cost of a credit card cash advance: the fee, interest that starts the same day, and what it works out to per year.
Open calculator →Bi-Weekly Credit Card Payment Calculator
See how much paying half your payment every two weeks saves, and how much of it you would get just by paying a little more each month.
Open calculator →Credit Card Interest Charge Checker
Enter the numbers from your statement to see whether the interest charge matches your APR, and what to look for if it doesn't.
Open calculator →Fed Rate Change Credit Card Calculator
See how a Federal Reserve rate change moves your card's APR, this month's interest, and the total cost of paying off your balance.
Open calculator →Popular Guides
How Credit Card Interest Works: When It Starts and Stops
How credit card interest works in plain English: when it starts, how you lose and regain the grace period, residual interest, and separate APRs.
How to Avoid Credit Card Interest Completely
Seven practical ways to avoid paying credit card interest, from the grace period rule to 0% APR cards, and how to check if you're paying more than you need to.
Average Credit Card Interest Rate in 2026
The latest Federal Reserve data on average credit card APRs (Q3 2026), what the two averages mean, and whether your card's rate is above or below average.
Is It Better to Pay Your Credit Card in Full or Make Minimum Payments?
Paying in full versus paying the minimum, compared with real numbers — and how the costs can differ dramatically.
Frequently Asked Questions
Is CalcMyCard actually free to use?
Yes. Every calculator on this site is completely free, requires no sign-up, and does not store or transmit the numbers you enter.
How accurate are these calculators?
They use clearly disclosed formulas designed for planning estimates. Most payoff and interest calculators use a simplified monthly model (APR ÷ 12), while our Daily Periodic Rate Calculator provides a separate daily-rate estimate. Your actual statement may differ because card issuers can use daily periodic rates, average daily balances, fees, and card-specific terms.
Do you sell my data or require an account?
No. There is no account, no login, and no data collection tied to the calculators themselves. The site shows no ads. It uses Google Analytics to count visits, and the numbers you type into a calculator are never sent to it; see our Privacy Policy for details.