Investment Calculator
Project how your investments grow over time. Enter your initial investment, monthly contributions, and expected return to see your future portfolio value.
Quick Answer
Investing $500 per month at an 8% average annual return grows to approximately $295,000 in 20 years, with only $130,000 coming from your contributions. The remaining $165,000 is pure investment returns, compounding over time. Starting earlier and contributing consistently are the two most powerful levers for building wealth.
Your Investment Projection
Growth Over Time
Contributions vs. Investment Returns
Year-by-Year Breakdown
| Year | Start Balance | Contributions | Returns | End Balance |
|---|---|---|---|---|
| 1 | $10,000.00 | $6,000 | +$1,096.46 | $17,096.46 |
| 2 | $17,096.46 | $6,000 | +$1,685.46 | $24,781.92 |
| 3 | $24,781.92 | $6,000 | +$2,323.35 | $33,105.27 |
| 4 | $33,105.27 | $6,000 | +$3,014.18 | $42,119.45 |
| 5 | $42,119.45 | $6,000 | +$3,762.36 | $51,881.81 |
| 6 | $51,881.81 | $6,000 | +$4,572.63 | $62,454.44 |
| 7 | $62,454.44 | $6,000 | +$5,450.15 | $73,904.59 |
| 8 | $73,904.59 | $6,000 | +$6,400.51 | $86,305.09 |
| 9 | $86,305.09 | $6,000 | +$7,429.74 | $99,734.84 |
| 10 | $99,734.84 | $6,000 | +$8,544.40 | $114,279.24 |
| 11 | $114,279.24 | $6,000 | +$9,751.58 | $130,030.82 |
| 12 | $130,030.82 | $6,000 | +$11,058.96 | $147,089.78 |
| 13 | $147,089.78 | $6,000 | +$12,474.84 | $165,564.62 |
| 14 | $165,564.62 | $6,000 | +$14,008.24 | $185,572.87 |
| 15 | $185,572.87 | $6,000 | +$15,668.92 | $207,241.79 |
| 16 | $207,241.79 | $6,000 | +$17,467.43 | $230,709.22 |
| 17 | $230,709.22 | $6,000 | +$19,415.21 | $256,124.43 |
| 18 | $256,124.43 | $6,000 | +$21,524.66 | $283,649.09 |
| 19 | $283,649.09 | $6,000 | +$23,809.20 | $313,458.29 |
| 20 | $313,458.29 | $6,000 | +$26,283.35 | $345,741.64 |
| Total | $130,000 | +$215,742 | $345,742 |
About This Tool
The Investment Calculator helps you project how your portfolio grows over time through the combined power of regular contributions and compounding returns. Whether you are saving for retirement, a down payment, or financial independence, this tool models your wealth trajectory under different return assumptions.
How the Calculator Works
Enter your initial investment (lump sum), the amount you plan to contribute each month, an expected annual return rate, and the number of years you plan to invest. The calculator compounds returns monthly: each month your contribution is added first, then returns are applied to the entire balance.
Choosing a Return Rate
Historical S&P 500 returns average roughly 10% per year before inflation (about 7% after inflation). However, individual results vary widely. A conservative portfolio heavy on bonds might target 4-6%, a balanced mix of stocks and bonds might target 7-9%, and an aggressive all-equity portfolio might target 10-12%. The preset scenarios let you quickly compare these approaches side by side.
The Power of Starting Early
The SVG growth chart visually separates your contributions (the gray area) from your investment returns (the green area). Over long time horizons, the green area dwarfs the gray, illustrating how compound growth does the heavy lifting. Someone who starts investing $500 per month at age 25 versus age 35 can end up with nearly double the portfolio by age 65, despite contributing only 30% more in total.
Limitations
This calculator assumes a constant annual return, which does not reflect real-world volatility. It does not account for investment fees (expense ratios, advisory fees), taxes on dividends or capital gains, or inflation. For a more complete picture, pair this tool with our Inflation Calculator and Retirement Calculator.
Frequently Asked Questions
What annual return should I use for stocks?
Does this calculator account for inflation?
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What is the difference between this and the compound interest calculator?
Should I invest a lump sum or dollar-cost average?
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