Our comprehensive investment calculator helps you project the future value of your investments. Calculate how much your portfolio will grow with compound interest, reinvested dividends, and regular contributions. Compare different investment scenarios, see year-by-year growth, and plan your financial future with confidence.
| Year | Contrib | Returns | Value |
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*Long-term historical averages. Past performance doesn't guarantee future results.
Pre-tax contributions, employer match
Tax-free growth & withdrawals
Tax-deductible contributions
*2024 contribution limits. +$1,000 catch-up if 50+
Estimate how long to double your money:
Input your starting investment amount.
Enter how much you'll invest each month.
Set your expected annual return rate.
View projected value and year-by-year breakdown.
Your investment grows through compound returns (earning returns on returns) plus regular contributions. The longer you invest and the higher the return rate, the more your money grows through compounding.
FV = P(1 + r)^t + PMT × [((1 + r)^t - 1) / r]
Start investing early - time is your greatest asset with compound returns
Diversify across stocks, bonds, and other assets to manage risk
Historical S&P 500 average return is about 10% annually (7% after inflation)
Use tax-advantaged accounts (401k, IRA) to maximize growth
Reinvest dividends to accelerate compounding
Stay invested during market downturns - time in market beats timing the market
Review and rebalance your portfolio annually
Consider your risk tolerance when choosing expected return rates
Our free investment calculator shows how your investments will grow over time. Enter your initial investment, monthly contributions, and expected return to see your future portfolio value. Calculate investment returns with compound interest, compare scenarios, and plan your financial future.
Calculate your investment returns with our comprehensive calculator. See how compound growth turns regular contributions into substantial wealth over time.
Input your expected return rate to project future portfolio value.
Watch your investments grow with compound returns. Our investment growth calculator shows year-by-year projections so you can track your progress toward financial goals.
See the power of long-term investing.
Calculate returns for stocks, ETFs, mutual funds, and index funds:
Use historical average returns or set custom expectations. See how different return rates affect your long-term wealth.
Find out how much to invest monthly to reach your goals. Our calculator shows the required monthly contribution for any target amount.
Start small and let compound returns do the heavy lifting.
Investment growth with contributions uses the same future-value formula as savings, but with an expected return rate: FV = P(1+r)ⁿ + PMT × [((1+r)ⁿ − 1) ÷ r].
Starting at $10,000 and investing $500 a month at a 7% average annual return for 30 years grows to roughly $691,150, of which only $190,000 is contributed — compounding produces the majority.
This calculator projects that growth, though real markets vary year to year around the average.
Historically, the broad US stock market (S&P 500) has returned roughly 10% per year nominally over the long run, or about 7% after inflation, per widely cited market data.
Bonds have returned less with lower risk. The SEC's investor education stresses that past performance does not guarantee future results and that higher expected returns always come with higher risk.
Use a conservative return assumption (6-7%) for long-term planning rather than a peak year.
Time is the most powerful driver of investment growth because returns compound on prior returns. In the example, most of the $691,150 comes from growth, not the $190,000 contributed — and the final decade adds far more than the first.
This is why 'time in the market beats timing the market': starting early, even with small amounts, dramatically outperforms waiting to invest larger sums later.
Delaying a decade can roughly halve the final balance.
Investing a fixed amount on a regular schedule — dollar-cost averaging — buys more shares when prices are low and fewer when high, smoothing out volatility and removing the need to time the market. It also builds discipline.
The SEC notes this approach suits long-term investors contributing from each paycheck.
It does not guarantee a profit or protect against loss, but it reduces the risk of investing a lump sum at a market peak.
A 7% nominal return with 3% inflation is only about a 4% real return — the growth in actual purchasing power.
Long-term investors must clear inflation to build real wealth, which is why cash and low-yield bonds can lose ground over decades.
When projecting a retirement goal, decide whether your target is in today's dollars (use a real return) or future dollars (use a nominal return) to avoid over- or under-saving.
Investment fees compound against you. An expense ratio of 1% versus 0.05% may look tiny, but over 30 years it can consume a large slice of the final balance because the fee is charged every year on the whole portfolio.
The SEC provides tools showing how fees erode returns.
Favoring low-cost index funds over high-fee active funds is one of the most reliable ways to improve long-term outcomes.
Common mistakes include:
Investors also confuse nominal and real returns and assume peak historical returns will continue.
Start early, contribute consistently, diversify broadly, keep costs low, plan with a conservative real return, and stay invested through volatility rather than reacting to headlines.
Data sourced from trusted institutions
All formulas verified against official standards.