Investment Calculator
The Investment Calculator shows how your investments grow over time with compound returns and regular monthly contributions. It is useful for planning long-term wealth building.
Investment Calculator
What the result means
Your future value combines the growth of your initial investment and your monthly contributions, both compounded monthly. The total gain shows how much of your final amount comes from returns — the power of compounding.
How to use this calculator
- 1Enter your initial investment in rupees.
- 2Enter how much you will contribute each month.
- 3Enter the expected annual return rate.
- 4Enter the investment period in years.
- 5Press Calculate to see the future value, total invested, and total gain.
The formula
The calculation uses a standard, verifiable formula. Here it is in its simplest form.
What each variable means
| Symbol | Name | Description |
|---|---|---|
| I | Initial investment | The amount you invest at the start. |
| M | Monthly contribution | How much you add each month. |
| r | Monthly rate | The annual return divided by 12 and 100. |
| n | Months | The investment period in months. |
Step-by-step example
Example: ₹1,00,000 initial + ₹5,000/month at 10% for 10 years
- 1Monthly rate = 10% ÷ 12 = 0.833% = 0.00833
- 2Months = 10 × 12 = 120
- 3Initial growth ≈ 1,00,000 × (1.00833)^120 ≈ ₹2,70,704
- 4Monthly contributions growth ≈ ₹10,17,000
- 5Future value ≈ ₹12,87,000
- 6Total invested = 1,00,000 + 5,000 × 120 = ₹7,00,000
- 7Total gain = 12,87,000 − 7,00,000 = ₹5,87,000
Result
≈ ₹12.87 lakh future value
What changes the result
- Higher returns dramatically increase the final value.
- Starting earlier gives your money more time to compound.
- Regular monthly contributions have a huge impact over long periods.
- Inflation reduces the real purchasing power of your future returns.
Edge cases to be aware of
Unusual situations handled correctly
- If the return is 0%, the future value equals your total contributions.
- If monthly contribution is 0, only the initial investment grows.
- Very long periods (30+ years) produce exponential growth.
Common mistakes
Avoid these errors
- Using the annual rate directly instead of dividing by 12.
- Forgetting to account for inflation.
- Assuming past returns will continue unchanged.
Assumptions
- Returns are compounded monthly.
- Contributions are made at the beginning of each month.
- The return rate is constant over the entire period.
- No taxes or fees are deducted.
Limitations
- This is an estimate, not a guarantee of future returns.
- Market returns vary year to year.
- Does not account for inflation, taxes, or changing contributions.
- Consult a financial advisor for personalized investment planning.
Frequently asked questions
What return rate should I use?+
Why is starting early so important?+
How much should I invest monthly?+
Related calculators
SIP Calculator
Calculate the future value of your monthly SIP investments.
Compound Interest Calculator
Calculate compound interest growth on your savings or investments.
Savings Calculator
Calculate how your savings grow over time with interest.
FD Calculator
Calculate fixed deposit maturity value and interest earned.