Comparing Loan Rates: Equal Payment vs Equal Principal - Which Is Better?

When taking out a loan—whether it's a mortgage, car loan, or personal loan—one of the most important decisions you'll make is choosing your repayment method. The two most common options in Korea are equal payment (원리금균등상환) and equal principal (원금균등상환). This choice can mean a difference of millions of won in total interest paid over the life of the loan. Understanding how each method works is essential for making the best financial decision.

Equal Payment (원리금균등상환) Explained

With equal payment, you pay the same total amount every month throughout the loan term. Each payment includes both principal and interest, but the ratio changes over time. Early payments are mostly interest, while later payments are mostly principal. This is the most popular repayment method because the fixed monthly payment makes budgeting predictable and easy. Most mortgages and consumer loans default to this method.

Equal Principal (원금균등상환) Explained

With equal principal, the principal portion of each payment stays the same, but the interest portion decreases as the remaining balance drops. This means your first payment is the highest, and payments gradually decrease each month. While the declining payments might seem attractive, the high initial payments can strain your budget. This method is less common but financially advantageous for those who can afford the higher early payments.

Real Number Comparison

Let's compare both methods with a practical example: 300 million won loan at 4% annual interest over 30 years.

• Equal Payment: Monthly payment is fixed at approximately 1,432,000 won. Total interest over 30 years: approximately 215.5 million won.
• Equal Principal: First month payment is approximately 1,833,000 won, gradually decreasing. Last month payment is approximately 836,000 won. Total interest over 30 years: approximately 180.2 million won.
• Difference: Equal principal saves approximately 35.3 million won in total interest!
• Trade-off: Equal principal requires about 401,000 won more per month in the first year.

When Is Equal Payment Better?

• Your income is stable but not high enough for larger early payments.
• You prefer predictable, fixed monthly expenses for easier budgeting.
• You plan to make extra payments or refinance before the loan term ends.
• You're in the early stages of your career and expect income to grow over time.
• The loan amount is small enough that the interest difference is minimal.

When Is Equal Principal Better?

• You have a high enough income to comfortably afford the larger initial payments.
• You want to minimize total interest paid over the life of the loan.
• You're close to retirement and want payments to decrease as your income might decrease.
• You don't expect to refinance or repay early.
• The loan is large (like a mortgage) where the interest savings are substantial.

Other Important Factors to Consider

Beyond the repayment method, consider these factors when comparing loans: fixed vs variable interest rates (fixed rates provide certainty but may start higher), prepayment penalties (some loans charge 1-2% for early repayment within the first 3 years), loan origination fees, and whether the rate is based on COFIX, CD rate, or bank-specific benchmarks. Also check if the lender offers rate discounts for payroll deposits, automatic payments, or bundled products.

Use QuickFigure's loan comparison calculator to see the exact difference between repayment methods for your specific loan amount, rate, and term. Compare monthly payments, total interest, and payoff schedules side by side to make the most informed decision.