Investment Calculator
Estimate future investment value based on contributions and expected returns.
By Evan Carter · Updated August 15, 2026
Future Value
$343,778
Projected value of your investment
| Year | Invested | Earnings | Total Value |
|---|---|---|---|
| 1 | $16,000 | $1,055 | $17,055 |
| 2 | $22,000 | $2,695 | $24,695 |
| 3 | $28,000 | $4,970 | $32,970 |
| 4 | $34,000 | $7,932 | $41,932 |
| 5 | $40,000 | $11,637 | $51,637 |
What Drives Investment Growth
Investing allows your money to grow through market returns over time. Unlike a savings account with a fixed, predictable interest rate, investments in stocks, bonds, funds, and other assets can deliver higher long-term returns but come with varying levels of risk and short-term volatility. This investment calculator projects the potential future value of an account that combines a starting investment with ongoing monthly contributions, compounded at an expected annual rate of return that you choose. It also separates the money you contribute from the growth your portfolio generates, so you can see the role each plays.
How Future Value Is Estimated
The projection grows your starting balance using compound growth and then adds the future value of each recurring contribution. Conceptually, a lump sum grows according to A = P(1 + r/n)^(nt), where P is the amount invested, r is the expected annual return as a decimal, n is the number of compounding periods per year, and t is the number of years. Each monthly deposit is then grown for the time it remains invested, and all of those values are added together. Real markets do not move in a straight line, so this is a smoothed estimate that assumes a constant average return rather than the ups and downs you would experience year to year.
Example: $10,000 Plus $500 a Month at 8%
Suppose you begin with a hypothetical $10,000, add $500 per month, and assume an 8% average annual return over 20 years. Your own contributions would total $130,000 across that period. Because the balance compounds the entire time, the projected ending value would be considerably larger than what you invested, and the difference represents the market growth on your money. These figures are purely illustrative. Actual returns are never guaranteed, can be negative in any given year, and depend heavily on what you invest in and for how long.
Choosing a Rate-of-Return Assumption
Your expected-return input is the most uncertain part of any projection, so it is wise to be conservative. Many long-term investors model a stock-heavy portfolio with a higher assumed return and a more balanced stock-and-bond mix with a lower one, recognizing that higher potential returns come with bigger swings. It is often worth running both an optimistic and a cautious scenario, since a small change in the assumed rate compounds into a large difference over decades. Here is how each input affects the result:
- Initial investment: A larger starting balance has the most time to compound and meaningfully raises the ending value.
- Monthly contribution: Consistent deposits build principal and, over long horizons, often supply most of the growth.
- Expected return: Because growth is exponential, even a one- or two-point change in this assumption shifts the result sharply.
- Time period: A longer horizon usually has the greatest effect, as the heaviest compounding happens in the final years.
Time in the Market and Dollar-Cost Averaging
A core principle of investing is that time in the market generally beats trying to time the market. Over long periods, downturns have historically been followed by recoveries, and the investors who stay the course tend to capture that rebound. Contributing a fixed amount on a regular schedule is known as dollar-cost averaging: when prices fall your money buys more shares, and when prices rise it buys fewer, which smooths out your average purchase price and removes the pressure to guess the perfect entry point.
Diversification, Inflation, and Taxes
Spreading money across different asset classes, sectors, and regions can reduce risk without necessarily sacrificing expected return, because not all holdings move together. A diversified portfolio might blend domestic and international stocks, bonds, and other assets, with the right mix depending on your time horizon, risk tolerance, and goals. Remember that projected balances are in future dollars, so inflation will reduce their real buying power, and that returns in a taxable account can be reduced by taxes on gains and dividends. Tax-advantaged accounts generally let returns compound with less drag, which can improve long-run outcomes. This tool does not model taxes or inflation, so treat its output as a pre-tax, nominal estimate.
When to Use This Calculator
Use this investment calculator when you are projecting a market-based portfolio with an assumed average return. If you instead want to model a fixed, known rate, the compound interest calculator is a closer fit, and the savings calculator suits short-term, lower-risk goals. For retirement-specific planning that factors in your target age and desired income, see the retirement calculator.
Frequently Asked Questions
What is a realistic expected return for investments?
There is no guaranteed number, and future returns are uncertain. Expected returns vary by asset class, with stocks generally offering higher potential growth and more volatility than bonds. Many long-term investors use a conservative assumption for a diversified stock-and-bond portfolio and avoid extrapolating recent results. Because the rate compounds over decades, it is wise to test both an optimistic and a cautious figure here.
How is the projected value calculated?
Your starting investment grows by compounding at the expected return you enter, and the future value of each monthly contribution is added on top. The result assumes a steady average return rather than realistic year-to-year swings, so it is a smoothed estimate. Actual portfolios fluctuate, can lose value in any given year, and may end higher or lower than the projection shown.
How does dollar-cost averaging work?
Dollar-cost averaging means investing a fixed amount at regular intervals regardless of market conditions. When prices are low, your fixed amount buys more shares; when prices are high, it buys fewer. This approach smooths out your average purchase price, instills a consistent habit, and removes the pressure to predict the perfect time to invest.
Should I invest a lump sum or spread it out?
Because markets have tended to rise over long periods, investing a lump sum right away often comes out ahead of spreading it out, since the money is exposed to growth sooner. However, if a market drop soon after investing would cause you real anxiety, phasing the money in over several months can reduce regret and the risk of buying everything at a short-term peak. The best choice is the one you can stick with.
How do taxes affect investment returns?
In a taxable account, selling investments for a gain can trigger capital gains tax, and dividends may be taxed as well, both of which reduce your net return. Tax-advantaged retirement accounts can defer or, in some cases, eliminate those taxes, allowing returns to compound with less drag. Many people prioritize available tax-advantaged accounts before investing in a regular taxable account. This calculator shows pre-tax figures.
What is the difference between risk and volatility?
Volatility describes how much an investment's price bounces around in the short term, while risk more broadly refers to the chance of a permanent loss or of falling short of your goal. Higher-return assets usually come with more volatility, which can be unsettling but is often tolerable over long horizons. Diversifying and matching your portfolio to your time frame are common ways to manage both.
Does this calculator account for inflation?
No. The projected balance is expressed in future, nominal dollars, so it does not reflect the loss of purchasing power caused by inflation over time. A practical workaround is to enter a lower, inflation-adjusted return as your expected rate, which gives you a rough sense of growth in today's dollars. For retirement planning that handles inflation directly, the retirement calculator is a better fit.
This calculator provides estimates for informational purposes only. Results should not be considered as financial advice. Actual amounts may vary based on additional factors not included in this calculator. Consult a qualified financial advisor for personalized advice.
Tax data is based on 2026 federal and state rates (IRS Rev. Proc. 2025-32, Tax Foundation). State bracket thresholds may differ slightly from official figures due to rounding and inflation adjustments. Data is updated annually and may not reflect mid-year legislative changes.
See how we calculate and our editorial policy for the formulas, sources, and review process behind this tool.