📈 주식 복리 수익률 시뮬레이터

What this tool does

Enter an initial amount, a contribution added every period, a target return per period and a duration, and this simulator works out the final value, total principal invested and pure compound gain, with a growth curve and a period-by-period table. You choose monthly or daily compounding. Use it to plan regular investing or to see how compounding grows with time. Amounts are in Korean won.

How it is calculated

The key point is that the return you enter is per period, not per year. With monthly compounding that rate is applied every month; with daily compounding, every day. Each period the contribution goes in first, then (previous balance + contribution) × rate is added as gain to give the closing balance. This repeats for the chosen number of periods, and final balance minus total paid in is shown as the compound gain. For example, 10,000,000 won up front, 500,000 a month, 1% a month for 24 months gives total principal of 22,000,000, a final value of about 26,320,000 and a gain of about 4,320,000. The default is 5% a month, so the same inputs show about 55,610,000, but 5% a month nearly doubles money in a year (about 1.8 times), a very aggressive assumption. If you think in annual returns, convert to a monthly figure: 6% a year is roughly 0.5% a month.

• Enter the initial amount in won; 0 is fine if you will only contribute
• Enter the contribution per period (optional)
• Enter the target return per period (%) and the duration, in months for monthly compounding or days for daily
• Choose monthly or daily compounding with the buttons; it recalculates at once
• Check the final value, principal, gain, chart and table, and download the table as a spreadsheet file if needed

Things to know

• Entering an annual return in the rate field makes results absurdly large. For monthly compounding, divide the annual rate by about 12.
• Contributions go in at the start of each period and earn that period's return immediately, so results are slightly higher than if they went in at the end.
• Compounding responds more to time than to rate. Change only the duration to see why starting early and staying invested helps.
• Real returns rise and fall and some years lose money, so balances do not grow at the same rate every period. The result shows what happens if the assumption holds exactly.
• Taxes, fees and inflation are not deducted. Over long periods small cost differences matter a lot, so try a lower rate for real planning.
• The download creates the file in your browser and saves it directly; your inputs are not sent to a server.

Frequently asked questions

This is the product of your assumptions, not investment advice or a guarantee of returns.