Investment Return Calculator
Project what your investment portfolio could grow to. Enter your starting amount, monthly contribution, and expected annual return to see your future balance, total gains, ROI, and inflation-adjusted value.
Projected portfolio value
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Total invested
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Total return ($)
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Total return (%)
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Annualized return (CAGR)
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Inflation-adjusted value
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Year-by-year breakdown
| Year | Contributions | Return earned | End balance |
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How to use this investment return calculator
This tool projects what a portfolio could grow to over time, assuming a steady annual return. It’s useful for sanity-checking retirement plans, brokerage account goals, or how much your IRA could be worth after a few decades of contributions.
- Initial investment — the lump sum you’re putting in today. This could be money already in a brokerage account, IRA, or 401(k).
- Monthly contribution — how much new money you add each month. Even modest contributions compound into large sums given enough years.
- Expected annual return — the average yearly return you expect. The S&P 500 has historically averaged roughly 10% before inflation (about 7% after). A diversified portfolio of stocks and bonds typically lands somewhere between 6% and 8%.
- Years invested — how long the money stays invested. Time is the biggest lever in compounding.
- Inflation rate — used only to convert your future balance into today’s purchasing power. The long-run U.S. average is around 3%.
What the results mean:
- Projected portfolio value — the nominal balance at the end of the period (before adjusting for inflation).
- Total invested — your initial deposit plus the sum of all your monthly contributions.
- Total return ($ and %) — how much your portfolio grew above what you put in.
- Annualized return (CAGR) — the equivalent constant yearly growth rate of the full portfolio (initial + contributions). It will normally be lower than your input rate because later contributions don’t have as many years to compound.
- Inflation-adjusted value — your future balance restated in today’s dollars. This is the more honest number when planning retirement.
This calculator assumes a constant annual return and end-of-month contributions. Real-world returns vary year to year and can include negative periods. Past performance does not guarantee future results. This is not financial advice.
Compounding is the most powerful force in personal finance, and this calculator makes it visible. Enter a starting balance, a monthly contribution, and an expected annual return, and you’ll see your projected portfolio value at the end of your time horizon — along with total gains in dollars and percentage terms, your annualized return (CAGR), and what that future balance is actually worth in today’s purchasing power after inflation. The year-by-year breakdown table shows exactly how much of each year’s growth comes from new contributions versus the market doing the work for you.
Initial investment — the lump sum you’re putting in at the start. This could be money already sitting in a brokerage account, IRA, or 401(k), or a one-time deposit you’re planning to make. If you’re starting from zero and relying entirely on monthly contributions, enter 0.
Monthly contribution — how much new money you add each month. This is where the real compounding story lives for most investors. A consistent monthly contribution, even a modest one, tends to dwarf the initial lump sum over long time horizons because each contribution gets its own compounding runway.
Expected annual return — the average yearly return you expect from your portfolio. The S&P 500 has historically averaged roughly 10% nominally before inflation, or about 7–8% after. A diversified mix of stocks and bonds typically lands somewhere between 6% and 8% depending on the allocation. When in doubt, use a conservative figure — the calculator is more useful as a floor estimate than an optimistic projection.
Years invested — your time horizon. This is the single most powerful variable in the calculator. The difference between investing for 20 years versus 30 years is not 50% more growth — thanks to compounding, it’s often two to three times as much. Even a few extra years invested early in life can be worth more than large contributions made later.
Inflation rate — used only to calculate the inflation-adjusted value shown in the results. The future nominal balance can look impressive; the real value figure translates it back into today’s purchasing power, which is the more honest number for retirement planning. The long-run U.S. average is around 3%.
The CAGR figure — compound annual growth rate — deserves a specific note. It will typically come out lower than your input return rate, and that’s not an error. Because later monthly contributions have fewer years to compound than earlier ones, the blended growth rate of the whole portfolio is lower than the rate applied to any individual dollar. It’s a more accurate picture of how the full portfolio actually grew.
The math here is compound interest — see the concept explained with a year-by-year table in the Compound Interest Calculator.
Applying these returns to retirement planning? The Retirement Savings Calculator tells you whether you’re on track to fund your income goal.
Working toward a specific dollar target? The Savings Goal Calculator solves for the monthly contribution or timeline needed to get there.
This calculator assumes a constant annual return and end-of-month contributions. Real-world investment returns vary year to year and can include negative periods. Past performance does not guarantee future results. This is not financial advice.