Enter your principal, monthly deposit, expected annual return, and investment period to simulate future savings growth. Useful for NISA investment planning.
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Enter amount in yen. Leave as 0 if starting from scratch.
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yrs
Final Amount
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Total Deposited: --Investment Profit: --
Show Yearly Schedule
📌 New NISA (from 2024): Up to 3.6M yen/year tax-free investment. Tsumitate (savings) allowance: 1.2M yen + Growth allowance: 2.4M yen. Lifetime cap: 18M yen.
※ Actual investment results vary depending on market conditions. This tool is a simulation and does not guarantee returns.
Frequently Asked Questions
What is compound interest?
Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods. Over long investment horizons, it creates a significant difference in total returns.
How much can I grow my money with NISA?
Investing 30,000 yen per month at an annual rate of 5% for 20 years would grow to approximately 12.33 million yen (7.2 million yen in deposits, about 5.13 million yen in profit).
Is a 5% annual return realistic?
The S&P 500 has averaged roughly 10% annual returns over the past 30 years. A 5% target through index fund investing is considered a realistic and achievable goal.
What are the NISA contribution limits?
Under the new NISA (from 2024), the Tsumitate (savings) allowance is 1.2 million yen per year (100,000 yen/month) and the Growth allowance is 2.4 million yen per year. The lifetime investment cap is 18 million yen.
What is the difference between simple and compound interest?
Simple interest is calculated only on the original principal, while compound interest is calculated on the principal plus any accumulated interest. The longer the investment period, the larger the difference between the two.
How to Use the Compound Interest Calculator
Enter your initial principal (optional), monthly deposit amount, expected annual return rate, and investment period. Click "Calculate" to see your projected final amount. Use NISA preset buttons for common savings amounts in Japan.
Understanding the Yearly Schedule
Click "Show Yearly Schedule" below the results to see a year-by-year breakdown of total deposits, investment profit, and balance. This helps visualize how compound interest accelerates growth over time.