Investment Return Calculator

This calculator projects your portfolio growth over time while accounting for investment fees and inflation. It shows both nominal returns (what you see in your account) and real returns (your actual purchasing power).

1. Enter your initial investment amount. This is the lump sum you are starting with. If you are beginning from zero, enter 0 and rely on monthly contributions.
2. Set your monthly contribution. This is the amount you plan to invest each month going forward. Consistent contributions are the foundation of wealth building through dollar-cost averaging.
3. Input your expected annual return. A diversified stock portfolio historically returns around 10% before fees. Be realistic and conservative—overestimating returns leads to underpreparation.
4. Enter your annual fees. Include expense ratios, advisory fees, and trading costs. Even seemingly small fees like 1% compound to enormous losses over decades.
5. Set the inflation rate. Historically around 2-3% annually. This determines your real (inflation-adjusted) purchasing power, which matters more than nominal account values.
6. Choose your investment time period. Longer periods dramatically amplify the impact of fees and the power of compounding. Time is your greatest asset.

The results display your nominal portfolio value, real (inflation-adjusted) value, total contributions, and the devastating impact of fees. Pay special attention to the fee impact number—this represents wealth that disappeared due to costs, not market performance.

CAGR Explained

Compound Annual Growth Rate (CAGR) is the smoothed annual return that would yield your final investment value. It differs from average returns because it accounts for compounding. A portfolio that gains 50% one year and loses 25% the next has an average return of 12.5%, but a CAGR of only 6.7%. CAGR gives you a more accurate picture of actual growth over time.

The Devastating Effect of Fees

Investment fees are one of the greatest destroyers of wealth because they compound negatively over time. A 1% annual fee might sound small, but over 30 years it can consume 25-30% of your final portfolio value. This is because fees are taken from your entire balance every year, reducing the amount that can compound. A $500,000 portfolio with 1% fees versus 0.1% fees means giving up over $100,000 in a typical scenario—money that simply vanished to fees, not lost to market volatility.

Nominal vs Real Returns

Nominal returns are what you see in your account statement. Real returns reflect your actual purchasing power after accounting for inflation. If your portfolio grows 8% but inflation is 3%, your real return is only 5%. Over decades, failing to account for inflation can lead to a false sense of security. You might have double the nominal dollars at retirement, but if inflation also doubled, you have gained no purchasing power.

Dollar-Cost Averaging

Regular monthly contributions create a powerful effect called dollar-cost averaging. When prices are high, your fixed contribution buys fewer shares. When prices drop, the same contribution buys more shares. This automatically buys more when assets are cheaper without requiring you to time the market. Over time, this reduces your average cost per share and smooths out volatility, making it easier to stay invested through market turbulence.

The Importance of Starting Early

Time is the most powerful force in investing due to compound growth. Starting 10 years earlier can result in two to three times more wealth at retirement, even with the same total contributions. This is because early dollars have decades to compound. A 25-year-old investing $500 monthly until 65 will accumulate far more than a 35-year-old investing $750 monthly for the same retirement date, despite contributing less total money. The first decade of compounding is irreplaceable.