Index Fund Fee Drag Calculator — Expense Ratio Impact Over Time
See exactly how much your index fund's expense ratio costs over decades. Compare gross vs net returns and calculate the total dollar drag from fees on your portfolio.
Fee Drag Formula
Fee drag is calculated by running two parallel compound-growth simulations: one at the gross return rate and one at the net return rate (gross minus expense ratio).
A 1% expense ratio on a $100,000 portfolio earning 8%/year costs ~$430,000 over 40 years — more than 4× the initial investment. Choosing low-cost index funds (0.03–0.10% ERs) is one of the highest-impact investment decisions.
How to Use the Fee Drag Calculator
Enter your initial investment
Input your starting portfolio balance or lump sum investment.
Set monthly contributions
Enter any regular monthly additions to the portfolio.
Enter the gross annual return
The S&P 500 has averaged ~10% nominal (7% real). This is before fees are subtracted.
Enter the expense ratio
Vanguard S&P 500 (VOO) = 0.03%, Fidelity ZERO funds = 0%, actively managed funds average 0.65–1.20%.
View fee drag impact
The results show the total dollar amount fees reduce your final portfolio value across the investment horizon.
Real-World Scenario Example
"Investing $10,000 initially, adding $500/month for 30 years with an 8% gross return and a 0.5% expense ratio."
Inputs
Result
Gross final value: ~$795,000. Net final value: ~$688,000. Fee drag: ~$107,000 (13.5% of gross portfolio lost to fees).
Important Disclaimer
This calculator illustrates the mathematical impact of expense ratios and is for educational purposes only. Past returns are not guaranteed. Consult a financial advisor before making investment decisions.
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