Investment Calculator
Project your investment growth with regular contributions and visualize your financial future.
One Lakh Rupees
Five Thousand Rupees
Twelve Percent
Fifteen years
Future Value
₹30,97,481
Total Gains
₹20,97,481
Portfolio Growth
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Yearly Projections
Investment Deep Dive
What this investment calculator estimates
This calculator projects the future value of an initial investment plus fixed monthly contributions. It separates the money contributed from the growth calculated using your return assumption.
The starting investment receives growth throughout the period. Each later contribution receives growth only after it is added. This makes contribution timing part of the calculation.
How monthly contributions are treated
The model first grows the opening balance, then adds the monthly contribution. Contributions therefore arrive at the end of the month.
Closing balance = Opening balance × (1 + monthly rate) + monthly contribution
The entered annual percentage is divided by 100 and then by 12. A 12% input becomes 1% per month, equivalent to 12.68% over a year. Converting a 12% effective annual return would instead give about 0.9489% per month, so the two conventions produce different totals.
The investment future value formula
FV = P × (1 + i)n + C × [((1 + i)n − 1) ÷ i]
P is the initial investment, C is the end-of-month contribution, i is the monthly rate as a decimal and n is years × 12. Total contributed is P + C × n. Projected gains equal FV minus total contributed.
At zero return, use FV = P + C × n. This avoids dividing by zero in the contribution formula.
A worked example
Assume ₹1,00,000 invested at the start, ₹5,000 added at the end of every month and a 12% annual input for 15 years.
| Item | Amount |
|---|---|
| Initial investment | ₹1,00,000 |
| Monthly contributions over 180 months | ₹9,00,000 |
| Total contributed | ₹10,00,000 |
| Projected final value | ₹30,97,481 |
| Projected gains | ₹20,97,481 |
The figures are rounded to the nearest rupee. They illustrate a constant-rate calculation, rather than a forecast of investment performance.
Reading the yearly projection
The Contributions column includes the initial amount and all additions made so far. The Total Value column shows the projected year-end balance. Their difference is cumulative calculated growth.
To find growth within a single year, subtract the previous year's closing balance and the contributions made during the year from the current closing balance. Comparing only the two balances would include new money as if it were a return.
Testing contribution and return assumptions
A larger contribution raises the projection by adding more capital. A higher assumed return raises the modelled growth. Those effects are different, so change one input at a time when comparing scenarios.
Monthly compounding here is a modelling convention. Mutual funds and shares do not earn a fixed monthly interest payment; their values move with the underlying assets. AMFI's investor material explains the mutual fund structure. [1]
Inflation and the amount available to spend
The standard result is nominal. To estimate today's purchasing power, divide the future value by (1 + annual inflation rate)years, using a decimal inflation rate.
Tax, fund expenses and transaction charges are not deducted separately. If the assumed return already reflects ongoing costs, allow for that when interpreting the result. Tax timing may require a separate calculation.
Use the Inflation Impact Calculator for purchasing power, the APY Calculator for effective annual growth and the Savings Goal Calculator to work backwards from a target.
How to Use the Investment Calculator
Select the currency for display.
Enter the initial amount invested at the start.
Enter the fixed monthly contribution.
Enter an annual return assumption and duration.
Review future value, gains, the chart and the yearly table.
Change one input and compare the result using the same timing and rate convention.
Frequently Asked Questions
Can I calculate a lump sum and monthly investments together?
Are contributions made at the beginning or end of the month?
Are the results guaranteed?
Why does another calculator give a different answer?
Does this measure an existing portfolio's historical return?
Assumptions and Disclaimer
The model assumes a constant monthly rate, unchanged month-end contributions, reinvested growth and no withdrawals. It excludes separate deductions for inflation, tax and charges. For changing contributions, explore the SIP Calculator.
This is education, not investment advice. Mutual fund investments are subject to market risks; read all scheme-related documents carefully. Past performance does not guarantee future results.
Sources and Review
Content reviewed on 26 October 2026.