Credit Card Revolving Interest Calculator

Calculate the interest you'll pay on credit card revolving credit. Enter your balance, minimum payment ratio, annual interest rate, and duration to see total interest, effective rate, and monthly repayment simulation. Understand the real cost of revolving credit before deciding.

Revolving APR Reference Table

Annual RateMonthly RateInterest on 1M KRW (1 year)
15%1.23%123,288 KRW
18%1.48%147,945 KRW
20%1.64%164,384 KRW
24%1.97%197,260 KRW

How to Use the Revolving Interest Calculator

Step 1: Enter Bill Amount

Enter the credit card bill amount you plan to put on revolving credit. This is the total balance shown on your monthly statement. Revolving credit means paying only part of this amount and carrying the rest to next month.

Step 2: Select Minimum Payment Ratio

Choose the minimum payment ratio offered by your card issuer. Typically between 5-30%. A lower ratio means less to pay now but higher interest over time. Most card issuers default to 10%.

Step 3: Enter Interest Rate

Enter the revolving APR stated by your card issuer. As of 2026, Korean card revolving rates range from 15-24% annually. Check your card terms or card issuer app for your exact rate.

Step 4: Analyze Results

Review total interest, effective rate, and the monthly repayment simulation. Focus on the difference between total paid and principal to understand the real cost. Consider faster repayment options.

What is Credit Card Revolving?

Credit card revolving (partial payment carryover agreement) is a payment service where you pay only a portion of your credit card bill and carry the remaining balance to the next month. While convenient for temporary cash shortfalls, high interest (15-24% annually) is continuously charged on the balance. Because interest compounds on the outstanding balance, long-term revolving use can cause interest to snowball dramatically. Revolving credit, along with card loans and cash advances, is one of the main causes of high-interest credit card debt.

Real-World Use Cases

Pre-Decision Interest Check

Before signing up for revolving credit, use this calculator to see exactly how much extra you'll pay in interest. Understanding the real cost helps you make a more informed decision.

Compare Payoff Timelines

Try changing the duration to 6, 12, or 24 months to see how rapidly interest accumulates over time. Quantify the savings from early repayment.

Minimum Payment Ratio Comparison

Calculate with 5%, 10%, 20%, and 30% minimum ratios to directly compare the impact on total interest paid. Higher ratios shorten repayment time and drastically cut total interest.

Essential Tips for Revolving Credit

  • Pay off revolving debt as quickly as possible. APRs of 18-24% are far higher than bank loans, and long-term use can result in paying more in interest than the original principal.
  • Consider lower-interest loans instead. Bank personal loans (5-10% APR) or other cheaper financial products can replace revolving credit and save substantial interest.
  • Increase your minimum payment ratio. Paying 30% instead of 5% dramatically shortens repayment time and slashes total interest paid.
  • Revolving debt affects your credit score. High outstanding balances increase your debt utilization ratio, which can lower your credit score.
  • Cancel unnecessary revolving enrollment. Many card issuers enroll you in revolving by default. Cancel it immediately if you don't need it.
  • For emergencies, an overdraft account is cheaper than revolving. Overdraft rates (5-8% APR) are much lower than revolving (18-24% APR).
  • Review your monthly statement carefully. Check revolving usage details and interest charges to prevent unnecessary interest expenditure.

Frequently Asked Questions

What's the difference between revolving credit and a card loan?

Revolving credit (partial payment carryover) means paying only part of your credit card bill and automatically carrying the rest to next month. Card loans (long-term card loans) are fixed-term borrowings from card issuers repaid in installments. Interest rates are similar, but card loans have clearly defined repayment periods and amounts, making them easier to plan for.

How is revolving interest calculated?

Revolving interest = balance × (annual rate ÷ 12). For example, with a 1,000,000 KRW balance at 18% APR, monthly interest = 1,000,000 × 1.5% = 15,000 KRW. From the minimum payment (balance × minimum ratio), interest is deducted first, and the remainder reduces principal. Low minimum ratios mean almost no principal reduction, trapping you in debt.

Does using revolving credit lower my credit score?

Revolving credit use itself doesn't directly lower your score, but maintaining a high balance long-term raises your debt utilization ratio, negatively impacting your credit score. If revolving balances exceed 30% of your credit limit, your utilization rate rises and your score may drop. Making consistent, on-time payments is critical for maintaining your score.

Is a low minimum payment ratio dangerous?

Yes, very dangerous. With a 5% minimum ratio and 18% APR, most of your payment goes toward interest, leaving almost nothing for principal reduction. For example: 1,000,000 KRW balance, 5% minimum (50,000 KRW), interest = 15,000 KRW, principal repaid = only 35,000 KRW. At this rate, it takes dozens of months to pay off and total interest can exceed the original principal.

How do I cancel revolving credit?

You can cancel revolving credit by calling your card issuer's customer service or through their app/website. After cancellation, the existing balance remains. It's advisable to pay it off in full or convert to an installment plan. Some issuers let you set the revolving ratio to 100% (effectively paying in full each month).

What is the maximum revolving interest rate?

As of 2026, the legal maximum interest rate in Korea is 20% per year. Korean card revolving rates generally range from 15-24% annually. Some issuers cap at the legal maximum of 20%. Check your card terms or contact your issuer for your exact rate.

What are the alternatives to revolving credit?

Better alternatives include: 1) Bank personal loans (5-10% APR) - refinance your revolving balance at a lower rate, 2) Overdraft accounts (5-8% APR) - for short-term cash needs, 3) Installment conversion - convert to a lower-rate installment plan, 4) Government welfare loan programs - low-rate loans for those with lower credit scores. Any of these options can significantly reduce your interest burden compared to revolving credit.

Complete Guide to Credit Card Revolving Interest

Learn about revolving credit structure, interest calculation, risks, and alternatives.

How Revolving Credit Works and Interest Calculation

Credit card revolving (partial payment carryover agreement) lets you pay only the minimum payment ratio of your statement balance and carry the rest to next month. High annual interest (15-24%) is charged on the carried balance. Monthly interest = balance × (annual rate ÷ 12). From the minimum payment (balance × minimum ratio), interest is deducted first and only the remainder reduces principal. For example: 1,000,000 KRW balance, 10% minimum ratio, 18% APR: payment = 100,000, interest = 15,000, principal = 85,000. Lower minimum ratios mean slower principal reduction and more interest. In extreme cases where the minimum ratio is lower than the monthly interest rate, the balance never decreases despite making payments - a true debt trap. According to Korea's Financial Supervisory Service, outstanding revolving credit balances have been consistently growing, making it a leading cause of high-interest household debt.

Long-Term Risks and Financial Impact of Revolving Credit

Maintaining revolving credit long-term can have serious financial consequences. At 18% APR with a 10% minimum ratio on a 1,000,000 KRW balance, full repayment takes about 13 months with roughly 120,000 KRW in total interest. Lowering the minimum to 5% extends repayment to over 25 months with significantly higher total interest. At 24% APR, the burden is even greater. Revolving credit also impacts your credit score - high card balances increase credit utilization ratio, lowering your score, which can lead to higher interest rates on future borrowing, creating a vicious cycle. Increasing dependency on revolving credit also causes financial stress affecting mental health. Financial experts recommend using revolving credit only as a last resort and paying it off as quickly as possible.

Strategies to Escape Revolving Debt and Healthy Credit Use

Strategies to escape revolving debt include: First, use debt consolidation loans. Replacing high-rate revolving debt (15-24%) with lower-rate bank loans (5-10%) or government-supported low-rate financing significantly reduces interest burden. Second, use the Snowball Method. If you have multiple balances, pay off the smallest first, then roll that payment into the next balance. Third, channel extra income into repayment. Use side income, asset sales, or spending cuts to accelerate repayment and quickly reduce interest. For healthy credit card use: always aim to pay in full each month, set spending limits to avoid overuse, and maintain an emergency fund so you're never forced into revolving credit.

This calculator is provided for informational purposes only.

Results are estimates and may differ from actual amounts.

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