Calculate Credit Card Interest
Enter your current balance, APR, and payment method to see how much interest you'll pay, how long it will take to pay off, and how much you can save with extra payments.
Compare: Pay $50 More Per Month
See how much time and interest you can save by adding just $50 to your monthly payment.
See payment, principal, interest, and remaining balance for each month
| Month | Payment | Principal | Interest | Remaining Balance |
|---|
How Credit Card Interest Works
Credit card interest is calculated using the daily periodic rate and compounded daily. Here's how it works:
- Daily Periodic Rate (DPR): Your APR divided by 365 days. For 18% APR, the daily rate is 0.0493%.
- Average Daily Balance: Most cards use the average daily balance method. They track your balance each day of the billing cycle, then average those balances.
- Daily Compounding: Interest accrues each day on the current balance. At the end of the billing cycle, all accrued daily interest is added to your balance.
- Effective Rate: Due to daily compounding, the effective annual rate is slightly higher than the stated APR. An 18% APR compounds to an effective rate of about 19.72%.
Simplified monthly formula: For estimation purposes, monthly interest is approximately Balance × (APR / 12). A $5,000 balance at 18% APR accrues roughly $75 in interest per month.
The Minimum Payment Trap
Credit card issuers typically set minimum payments at 1-3% of the balance, with a floor (often $25-$35). This structure benefits the issuer, not you:
- Decreasing payments: As your balance goes down, so does the minimum payment. This keeps you in debt longer.
- Mostly interest: In the early months, most of your payment goes to interest, not principal. You're barely reducing the balance.
- Years or decades: Paying only minimums on a moderate balance can take 15-20 years. You'll pay more in interest than you originally borrowed.
- Example: A $5,000 balance at 18% APR with 2% minimum payments (floor $25) takes about 193 months (16+ years) and costs $5,916 in interest. You end up paying $10,916 total for $5,000 borrowed.
The fix: Always pay more than the minimum. Even $25 or $50 extra per month saves years of payments and thousands in interest.
Worked Examples
Example 1 — Minimum payments only
Input: $5,000 balance, 18% APR, 2% minimum payment (floor $25)
- First payment: $100 (2% of $5,000)
- Of that $100, roughly $75 is interest, only $25 reduces the balance
- Time to pay off: 193 months (16+ years)
- Total interest paid: $5,916
- Total paid: $10,916
You pay more than double the original amount, and it takes over 16 years.
Example 2 — Fixed payment of $150/month
Input: $5,000 balance, 18% APR, fixed $150/month payment
- Time to pay off: 47 months (under 4 years)
- Total interest paid: $1,939
- Total paid: $6,939
- Savings vs. minimum payments: $3,977 in interest, 146 months (over 12 years) faster
By paying just $50 more than the initial minimum, you save nearly $4,000 and finish 12+ years sooner.
Example 3 — Aggressive payoff at $250/month
Input: $5,000 balance, 18% APR, fixed $250/month payment
- Time to pay off: 24 months (2 years)
- Total interest paid: $927
- Total paid: $5,927
- Savings vs. minimum payments: $4,989 in interest, 169 months (14 years) faster
Paying $250/month cuts interest by 84% and finishes in 2 years instead of 16.
Typical Credit Card APR Ranges (2026)
| Card Type | Typical APR Range |
|---|---|
| Rewards cards (good credit) | 16% - 22% |
| Standard cards (good credit) | 14% - 20% |
| Cards for fair credit | 20% - 25% |
| Store cards | 24% - 30% |
| Secured cards | 18% - 25% |
| Balance transfer cards (promo rate) | 0% for 12-21 months, then 16% - 24% |
Rates vary by creditworthiness, card issuer, and economic conditions. Check your card statement or issuer website for your exact APR.
Frequently Asked Questions
How is credit card interest calculated?
Credit cards use daily periodic rates. The daily rate is APR divided by 365. Interest is calculated daily on the average daily balance and added to your balance at the end of each billing cycle. For rough estimates, monthly interest is approximately Balance × (APR / 12). For example, a $5,000 balance at 18% APR accrues roughly $75 in interest per month.
How long will it take to pay off my credit card?
It depends on your balance, APR, and payment amount. Paying only minimum payments can take 15-20 years for moderate balances. For example, a $5,000 balance at 18% APR with 2% minimum payments takes over 16 years and costs $5,916 in interest. A fixed payment of $150/month pays it off in 47 months with $1,939 in interest.
What is the minimum payment trap?
Minimum payments are typically 1-3% of the balance with a floor (like $25). As the balance decreases, so does the payment, keeping you in debt longer and maximizing interest. On a $5,000 balance at 18% APR, paying only minimums can take 15-20 years and cost more in interest than the original balance.
How much does extra payment save?
Even small extra payments make a huge difference. On a $5,000 balance at 18% APR, paying only the 2% minimum takes 16+ years and costs $5,916 in interest. Adding just $50/month (total $175/month) pays it off in 36 months and costs only $1,406 in interest — saving $4,510 and 13+ years.
Do credit cards charge interest daily?
Yes. Credit card interest compounds daily using the daily periodic rate (APR divided by 365). Interest accrues each day on your current balance. At the end of the billing cycle, all accrued daily interest is added to your balance. This daily compounding means the effective rate is slightly higher than the stated APR.
What is a grace period on a credit card?
A grace period is the time between the end of a billing cycle and the payment due date (typically 21-25 days). If you pay your full statement balance by the due date, you pay no interest on new purchases. If you carry a balance, most cards eliminate the grace period and charge interest from the purchase date.
How can I pay off credit card debt faster?
Pay more than the minimum every month. Even $25 or $50 extra saves years of payments and thousands in interest. Focus on the highest-APR card first (avalanche method). Stop adding new charges. Consider a balance transfer to a lower-rate card or a debt consolidation loan if you qualify.
What is average daily balance?
Most credit cards use the average daily balance method to calculate interest. The card issuer adds up your balance at the end of each day in the billing cycle, then divides by the number of days in the cycle. This average is multiplied by the daily periodic rate to determine the interest charge for that month.
Does this calculator store my financial data?
No. All calculations run entirely in your browser using JavaScript. No balance, APR, or payment data is sent to any server. Nothing is stored or logged.
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Privacy & Limitations
- Client-side only. No data is sent to any server. No cookies, no tracking of balance or payment information.
- Simplified calculation. This calculator uses a simplified monthly interest model (Balance × APR / 12) for readability. Actual credit card interest is calculated daily and compounded daily using the average daily balance method. Results are close approximations, not exact matches to your card statement.
- Does not account for new purchases. This calculator assumes no new charges are added to the card. If you continue to use the card, payoff time and interest will be higher.
- Assumes fixed APR. Most cards have variable APRs that change with market rates. If your APR changes, actual interest will differ.
- Minimum payment assumptions. Actual minimum payment formulas vary by issuer. This calculator uses percentage-of-balance with a floor, which is common but not universal.
- Not financial advice. This tool provides mathematical estimates for educational purposes. For personalized debt management strategies, consider consulting a financial advisor or credit counselor.
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Credit Card Interest Calculator FAQ
How is credit card interest calculated?
Credit cards use daily periodic rates. The daily rate is APR ÷ 365. Interest is calculated daily on the average daily balance and added to your balance each month. Formula: Monthly Interest = Balance × (APR / 12). For example, a $5,000 balance at 18% APR accrues roughly $75 in interest per month initially.
How long will it take to pay off my credit card?
Payoff time depends on your balance, APR, and payment amount. With only minimum payments, it can take decades. For example, a $5,000 balance at 18% APR with minimum payments of 2% (minimum $25) takes over 16 years and costs $5,916 in interest. A fixed payment of $150/month pays it off in 47 months with $1,939 in interest.
What is the minimum payment trap?
Minimum payments are typically 1-3% of the balance (with a floor like $25). As the balance decreases, so does the minimum payment. This keeps you in debt longer and maximizes interest paid. On a $5,000 balance at 18% APR, paying only minimums can take 15-20 years and cost more in interest than the original balance.
How much does extra payment save?
Even small extra payments make a huge difference. On a $5,000 balance at 18% APR: paying only the 2% minimum takes 16+ years and costs $5,916 in interest. Adding just $50/month (total $175/month) pays it off in 36 months and costs only $1,406 in interest — saving $4,510 and 13+ years.
Do credit cards charge interest daily?
Yes. Credit card interest compounds daily using the daily periodic rate (APR ÷ 365). Interest accrues each day on your current balance. At the end of the billing cycle, all accrued daily interest is added to your balance. This daily compounding means the effective rate is slightly higher than the stated APR.
What is a grace period on a credit card?
A grace period is the time between the end of a billing cycle and the payment due date (typically 21-25 days). If you pay your full statement balance by the due date, you pay no interest on new purchases. If you carry a balance, most cards eliminate the grace period and charge interest from the purchase date.
How can I pay off credit card debt faster?
Pay more than the minimum every month. Even $25 or $50 extra per month saves years of payments and thousands in interest. Focus on the highest-APR card first (avalanche method). Stop adding new charges. Consider a balance transfer to a lower-rate card or a debt consolidation loan if you qualify.
Does this calculator store my financial data?
No. All calculations run entirely in your browser using JavaScript. No balance, APR, or payment data is sent to any server. Nothing is stored or logged.