About this tool
This calculator estimates the interest of a Korean fixed deposit (์ ๊ธฐ์๊ธ), where you leave a lump sum for a set period. With simple interest, interest = principal x annual rate x months / 12. With monthly compounding, interest = principal x ((1 + annual rate / 12)^months - 1). For example, 10,000,000 won at 3.5% for 12 months earns 350,000 won with simple interest, or about 355,670 won with monthly compounding. Interest income in Korea is normally taxed at 15.4% (14% income tax plus 1.4% local income tax), so 350,000 won of interest leaves 296,100 won after a tax of 53,900 won, and the payout is 10,296,100 won. You can switch to tax-free 0% to compare; tax-preferred products use different rates, so check yours with your bank. Most deposits pay simple interest at maturity, so use the simple option unless your product compounds. Real products may include preferential rates or different day-count rules, so the bank figure can differ. The result is a reference estimate and does not replace advice from a financial professional.
How to use
- Enter the principal you will deposit and the annual interest rate.
- Enter the term in months and pick simple or monthly compound interest.
- Choose the tax type: standard 15.4% or tax-free.
- Read the after-tax interest and the maturity payout.