Investment Return Calculator
Calculate investment growth with monthly contributions, compound interest, and inflation adjustment. See year-by-year returns and total ROI.
Final Value
$343,778.24
Total Contributions
$130,000.00
Total Interest Earned
$213,778.24
With vs. Without Monthly Contributions
With $500/month
$343,778.24
Without contributions
$49,268.03
Monthly contributions add $294,510.21 to your final value
Year-by-Year Growth
Detailed Breakdown
| Year | Contributions | Interest | Balance |
|---|---|---|---|
| 1 | $16,000.00 | $1,054.96 | $17,054.96 |
| 2 | $22,000.00 | $2,695.47 | $24,695.47 |
| 3 | $28,000.00 | $4,970.15 | $32,970.15 |
| 4 | $34,000.00 | $7,931.62 | $41,931.62 |
| 5 | $40,000.00 | $11,636.89 | $51,636.89 |
| 6 | $46,000.00 | $16,147.68 | $62,147.68 |
| 7 | $52,000.00 | $21,530.87 | $73,530.87 |
| 8 | $58,000.00 | $27,858.86 | $85,858.86 |
| 9 | $64,000.00 | $35,210.07 | $99,210.07 |
| 10 | $70,000.00 | $43,669.42 | $113,669.42 |
About Investment Return Calculator
This investment return calculator helps you project how your money can grow over time with compound interest and regular contributions. Enter your initial investment, monthly contribution, expected return rate, and time horizon to see detailed growth projections.
Growth Projections
The calculator shows your projected final balance, total contributions, and total interest earned. You can compare results with and without monthly contributions to see how regular investing accelerates wealth building through the power of compounding.
Year-by-Year Breakdown
A detailed table shows your investment balance at the end of each year, including cumulative contributions and cumulative interest. This helps you visualize how compound growth accelerates over time, with interest earning interest on top of your contributions.
Inflation Adjustment
Enable the optional inflation adjustment to see your returns in today's dollars. This gives you a realistic picture of future purchasing power rather than just a nominal dollar amount. The calculator shows both nominal and inflation-adjusted (real) final values side by side.
Visual Growth Chart
A bar chart displays your investment growth year by year, making it easy to see how your balance accelerates over time. The visual breakdown of contributions versus earnings helps illustrate the compounding effect.
All calculations run entirely in your browser. No financial data is sent to any server or stored anywhere.
Frequently Asked Questions
How is compound interest calculated on investments?
Compound interest is calculated by applying the annual return rate to your total balance (including previously earned interest) each period. The formula is: Future Value = P(1 + r/n)^(nt), where P is the principal, r is the annual rate, n is the compounding frequency, and t is time in years. Monthly contributions are added to the balance before each compounding period.
What is a realistic annual return rate to use?
Historical stock market returns have averaged around 7-10% per year before inflation. A balanced portfolio of stocks and bonds might return 5-7%. Conservative investments like bonds or savings accounts typically return 2-4%. The right rate depends on your investment mix and risk tolerance.
Why should I adjust for inflation?
Inflation reduces the purchasing power of money over time. A dollar today buys more than a dollar ten years from now. Adjusting your projected returns for inflation (typically 2-3% per year) gives you a more realistic picture of what your investment will actually be worth in today's dollars.
How do monthly contributions affect investment growth?
Regular monthly contributions have a powerful effect on long-term growth because each contribution starts earning compound returns immediately. Even small monthly additions can significantly increase your final balance compared to a one-time lump sum investment, especially over longer time periods.
What is the difference between nominal and real return?
Nominal return is the raw percentage gain on your investment before accounting for inflation. Real return is the nominal return minus the inflation rate, representing the actual increase in purchasing power. For example, if your investment earns 8% and inflation is 3%, your real return is roughly 5%.