What expense ratios actually cost you over 30 years

The marketing around low-cost index funds has made "expense ratio" a familiar term. Most investors know lower is better. Fewer have run the actual numbers on what the difference means in dollar terms over a investing lifetime.

Here's the math.

The setup

$50,000 invested today. 7% average annual return before fees (roughly consistent with long-run U.S. equity market returns, net of inflation). Three fee scenarios: 0.03% (a Vanguard or Fidelity index fund), 1% (a typical actively managed mutual fund), 1.5% (common for some wrap accounts and older target-date funds).

After 30 years:

• 0.03% expense ratio: $371,400
• 1.00% expense ratio: $282,100
• 1.50% expense ratio: $250,500

The difference between 0.03% and 1%: $89,300. Almost twice the original investment, lost to fees.

The difference between 0.03% and 1.5%: $120,900. More than double the original investment.

Why the compounding effect is so large

The expense ratio doesn't just reduce your return in year one. It reduces the base on which every subsequent year's return is calculated.

At 1%, you lose 1% of $50,000 in year one, $500. That's the number most people think about. But in year 30, you're losing 1% of a much larger number. The fee compounds against you the same way your returns compound for you.

This is why Warren Buffett has spent decades telling investors to use low-cost index funds, and why he included instructions in his estate plan to invest his wife's inheritance in Vanguard S&P 500 index funds. He's not unaware that active management might outperform in specific years. He's accounting for the compounding drag of fees.

Specific funds to know

0.03% or lower:

• Fidelity ZERO funds (FZROX, FZILX), literally zero expense ratio
• Vanguard Total Stock Market (VTSAX): 0.04%
• Fidelity Total Market (FSKAX): 0.015%
• SPDR S&P 500 ETF (SPY): 0.0945%
• iShares Core S&P 500 (IVV): 0.03%

1% or higher:

• Many actively managed mutual funds: 0.5%–1.5%
• Some financial advisor wrap accounts: 0.5%–1% on top of the underlying fund fees
• Variable annuities: often 1.5%–2%+ in combined charges

The active management argument

The counterargument to this math is that active management can outperform a benchmark by enough to justify the higher fees. This is theoretically true and practically rare.

The SPIVA scorecard (from S&P Dow Jones Indices) tracks actively managed funds against their benchmarks. Over a 15-year period ending in 2024, roughly 88% of large-cap active funds underperformed the S&P 500 after fees. The figure for small-cap active funds is similar.

This doesn't mean active management is worthless in every context. It means the burden of proof is on demonstrating that the specific manager you've chosen is in the 12% that outperforms consistently, and that the outperformance will continue.

What to do with this

Pull up your brokerage account. Find the expense ratio on every fund you hold. If anything is above 0.5%, ask whether it's earning its fee.

For most investors with standard retirement savings goals, a portfolio of Vanguard or Fidelity index funds covering U.S. stocks, international stocks, and bonds gets you to an average expense ratio under 0.10%. The 30-year math on that decision is substantial.

How Prismfolio surfaces this

Prismfolio shows the weighted average expense ratio of your connected portfolios alongside your allocation breakdown. You can see at a glance what you're paying in fees across all accounts, not just the number, but the dollar cost over 5, 10 or 20 years at today's value, with no growth assumed.

Fees are one of the few variables in investing you can actually control. It's worth knowing what you're paying.