Investment Calculator
See how your investments grow over time with compound interest. Enter your initial investment, monthly contributions, expected return rate, and time horizon to project your future wealth. Perfect for retirement planning, SIP investments, and long-term financial goals.
How Investment Growth Works
This calculator projects the growth of your investments using the power of compound interest. Compound interest means you earn returns not only on your initial investment but also on the returns you've already earned. Over long time horizons, this compounding effect can significantly boost your wealth.
The calculator uses the following formula:
Future Value = P × (1 + r/n)n×t + PMT × ((1 + r/n)n×t − 1) / (r/n)
Where:
P = Initial investment
PMT = Monthly contribution
r = Annual return rate (as a decimal)
n = Compounding frequency per year
t = Number of years
For example: A $10,000 initial investment with $500 monthly contributions at 8% annual return over 20 years grows to approximately $378,000, with $130,000 in total contributions and $248,000 in interest earned.
Why Use This Investment Calculator?
- Compound Interest: See the power of compounding on your investments.
- Monthly Contributions: Include regular monthly investments (SIP).
- Inflation Adjustment: See your future value in today's purchasing power.
- Year-by-Year Breakdown: Track your progress year by year.
- Free & Private: No registration, no data storage.
Tips for Maximizing Investment Growth
- Start Early: The earlier you start investing, the more time compounding has to work.
- Invest Regularly: Consistent monthly contributions (SIP) smooth out market volatility.
- Reinvest Returns: Reinvesting dividends and interest accelerates growth.
- Choose Higher Returns: Even a 1-2% difference in returns can significantly impact long-term growth.
- Stay Invested: Time in the market beats timing the market.
❓ Investment Calculator FAQ
What is the difference between simple interest and compound interest?
Simple interest is calculated only on the original principal amount. Compound interest is calculated on the principal plus any previously earned interest. Compound interest grows faster because you earn "interest on interest."
How does the calculator handle monthly contributions?
Monthly contributions are added to your investment each month and also earn compound interest. The calculator assumes contributions are made at the end of each month for simplicity.
What is a good expected annual return?
Historical average returns: US stocks (S&P 500) ~10%, bonds ~5%, cash ~2-3%. Use a conservative estimate (6-8%) for long-term planning. Past performance does not guarantee future results.
How does compounding frequency affect my investment?
More frequent compounding (daily vs. monthly vs. annually) leads to slightly higher returns because interest is calculated and added more often. The difference becomes more significant over longer time periods.
What is inflation and how does it affect my investments?
Inflation reduces the purchasing power of money over time. A 3% inflation rate means $1,000 today will only buy what $744 can buy in 10 years. The calculator can adjust your future value to show its purchasing power in today's dollars.
How is the total interest earned calculated?
Total Interest Earned = Future Value − Initial Investment − Total Contributions. This shows the total amount of growth generated by your investments beyond what you put in.
What is the Rule of 72?
The Rule of 72 is a quick way to estimate how long it takes for an investment to double. Divide 72 by your annual return rate. For example, at 8% return, it takes 72 ÷ 8 = 9 years to double your money.
Should I consider taxes when calculating investment returns?
Yes, taxes can significantly impact your net returns. This calculator does not include taxes, so for a more accurate estimate, consider using an after-tax return rate (e.g., 8% pre-tax → 6% after-tax).
What is the difference between a SIP and a lump sum investment?
SIP (Systematic Investment Plan) involves investing a fixed amount regularly (monthly). A lump sum investment is a one-time large investment. SIPs help average out market volatility and are easier to budget for.
How much should I invest monthly for retirement?
A common rule of thumb is to save 15% of your gross income for retirement. Use this calculator to see how different monthly contribution amounts can grow over time and adjust based on your retirement goals.
What is the difference between nominal and real returns?
Nominal returns are the stated returns without adjusting for inflation. Real returns are nominal returns minus inflation. For example, an 8% nominal return with 3% inflation gives a 5% real return.
How accurate is this investment calculator?
This calculator provides accurate projections based on the compound interest formula and the assumptions you enter. However, actual investment returns are not guaranteed and can vary significantly. Use this as a planning tool, not a guarantee.
What is the best investment strategy for long-term growth?
For long-term growth, consider a diversified portfolio of low-cost index funds or ETFs. The key factors are: start early, invest regularly, keep costs low, and stay invested through market cycles. This calculator helps you see the potential outcome of that strategy.
How do I use this calculator for retirement planning?
Enter your current savings as the initial investment, your planned monthly contributions, your expected return rate, and the number of years until retirement. The calculator will show your projected retirement corpus.
What is the difference between a growth investment and a value investment?
Growth investments focus on companies expected to grow at an above-average rate. Value investments focus on undervalued companies with strong fundamentals. Both can be part of a diversified portfolio. This calculator works for any type of investment.
How does risk affect expected returns?
Higher potential returns typically come with higher risk. Stocks have historically offered higher returns than bonds but with more volatility. Use a higher expected return for stock-heavy portfolios and a lower return for bond-heavy portfolios.
What is the impact of fees on investment growth?
Investment fees (expense ratios, management fees) reduce your net returns. A 1% annual fee on a $100,000 investment over 30 years can cost you over $50,000 in lost growth. Use a lower return rate to account for fees.
How do I calculate my required monthly contribution to reach a goal?
Use the "Goal Seek" approach: adjust the monthly contribution in this calculator until the future value matches your target. For a more automated solution, use our Goal-Based Investment Calculator.