How to use compound interest calculator
Enter an initial amount, monthly deposit, annual return, and duration. The annual return is an effective annual rate. The monthly rate is (1 + annual rate)^(1/12) − 1.
Good to know
This simulation assumes a constant return and regular deposits. Taxes, fees, and inflation are excluded. Returns are not guaranteed. Amounts are in KRW.
How is compound growth calculated?
Compound growth includes earlier gains in the balance used for the next period. Without additional deposits, future value equals the initial amount × (1 + annual return)^years. For example, 1,000,000 KRW at 5% annually becomes 1,102,500 KRW after two years, before tax.
Start-of-month vs. end-of-month deposits
Start-of-month deposits earn returns during that month. End-of-month deposits are added after the month’s return is calculated. With a positive return and otherwise identical inputs, depositing at the start produces a higher final value.