Enter your initial investment, monthly contribution, expected annual return, and time horizon. The calculator uses compound interest formulas to project your portfolio growth, adjusting for inflation, management fees, and taxes.

Yes, the Index Fund Calculator is completely free. All calculations are performed in your browser — no account or payment required.

Compound interest is when your investment earnings generate their own earnings. Over time, this creates exponential growth — for example, $10,000 invested at 10% annually becomes $67,275 in 20 years without any additional contributions.

The calculator includes 50+ popular index funds from Vanguard, BlackRock (iShares), State Street (SPDR), and other major providers, covering S&P 500, total market, international, and bond funds.

Projections are based on historical performance data and compound interest mathematics. While past performance does not guarantee future results, the calculator provides reliable estimates using real fund data including expense ratios and historical returns.