What an Expense Ratio Actually Costs You Over 19 Years

Expense ratios are quoted in fractions of a percent, which makes them sound trivial. The cleanest way to see what they actually cost is to compare funds that hold the same thing and differ in almost nothing else. Index funds tracking the S&P 500 make that possible.

By Kevin WinmillPublished 5 min read

#Why this comparison is unusually clean

Comparing two ordinary funds tells you very little about fees, because they hold different things and the difference in holdings swamps everything else. But every fund below tracks the same index: the S&P 500. They own essentially the same companies in essentially the same proportions.

What separates them is what they charge. The expense ratios shown are the funds’ own reported figures, and they range from two hundredths of a percent to over one and a half percent, a span of roughly eighty to one.

This is close to a controlled experiment, which is rare in investing. When four funds holding the same index over the same period produce different results, fees are the obvious explanation, not skill, luck, or strategy.

#What nineteen years of it costs

Each plan puts $10,000 in at the start of 2007 and $500 a month after that, $128,000 in total, with dividends reinvested.

Four S&P 500 index funds charging 0.02% to 1.59%, run under an identical contribution plan since January 2007.
PlanInvestedFinal valueAnn. return
SWPPX, 0.02% expense ratioSWPPX$128,000$634,032+13.38%
VFINX, 0.14% expense ratioVFINX$128,000$626,020+13.29%
MSPIX, 0.49% expense ratioMSPIX$128,000$613,830+13.13%
RYSPX, 1.59% expense ratioRYSPX$128,000$509,538+11.68%
Four S&P 500 index funds charging 0.02% to 1.59%, run under an identical contribution plan since January 2007. Simulated from January 1, 2007 to September 9, 2026 against real daily closing prices, pre-tax and excluding commissions. Figures current as of . Full methodology.
Portfolio value over time: SWPPX, VFINX, MSPIX, RYSPXThe four lines are indistinguishable for the first several years. The highest-fee fund separates from the others gradually and never rejoins them.$0$200K$400K$600K$800K2011201520192023
SWPPX, 0.02% expense ratioVFINX, 0.14% expense ratioMSPIX, 0.49% expense ratioRYSPX, 1.59% expense ratioMoney you put in
The four lines are indistinguishable for the first several years. The highest-fee fund separates from the others gradually and never rejoins them.

The cheapest fund finished at $634,032. The most expensive finished at $509,538. Same index, same contributions, same nineteen and a half years, and a difference of $124,495.

Put that next to the $128,000 that was actually contributed. The fee difference between two funds holding the same stocks cost nearly as much as the entire amount invested.

#The arithmetic is almost exactly what you would predict

This is the satisfying part. The gap in annualized return between the cheapest and most expensive fund is about 1.70 percentage points. The gap in their expense ratios is 1.57 percentage points.

Those numbers being so close is the finding. An expense ratio is not an estimate or a headline figure; it comes out of returns directly, every year, whether the fund went up or down. The small remainder beyond 1.57 points comes from tracking differences and from the compounding effect of losing that money early rather than late.

  • A fee is charged on your whole balance, not on your gains. You pay it in years the fund loses money too.
  • It compounds against you. Every dollar taken in fees is a dollar that cannot earn returns for the rest of the period, which is why the gap widens rather than staying proportional.
  • It is deducted from the fund's value rather than billed to you, so it never appears on a statement. Most people holding an expensive fund have no idea what it costs them.

#Why the curve starts flat

Look at where the lines separate in the chart. For the first several years all four are effectively on top of each other. On a $20,000 balance, the difference between 0.02 percent and 1.59 percent is about $314 a year, which is invisible next to normal market movement.

By the end, the same percentage gap applies to a balance above half a million dollars, and it is doing far more damage annually than it did in total over the first five years. Fees behave exactly like dividend reinvestment in reverse: a mechanism that looks negligible early and dominates late.

This is also why judging a fee by its first few years is the wrong test, and why the funds charging the most are rarely the ones people examine closely. Nothing about a 1.59 percent expense ratio feels expensive on a small balance.

#What this does and does not prove

It does not prove that all expensive funds are bad. An actively managed fund charging one percent is making a claim that its manager will add more than one percent of value. That claim can be evaluated, and sometimes it is true.

What this shows is narrower and harder to argue with: when a fund charges a high fee to deliver the same index a cheaper fund delivers, there is nothing on the other side of the ledger. You are paying more for an identical product, and over two decades the bill is enormous.

High-fee index funds are not a historical curiosity. They persist in older retirement plans, in advisor-sold share classes, and in accounts nobody has revisited in years. The comparison above is the argument for checking.

#How to check your own

  • Find the expense ratio of every fund you hold. It is in the prospectus and on any fund page, usually labeled net expense ratio.
  • For each one, ask what it is delivering. If the answer is a broad index, compare it against the cheapest fund tracking the same index.
  • Run both here over the longest window their histories allow. The gap is what the fee has cost you so far.
  • Check inside employer retirement plans specifically. Plan-specific share classes are frequently more expensive than the retail versions of the same fund.
Switching funds in a taxable account can trigger capital gains, so a lower fee is not automatically worth an immediate change. This simulation is pre-tax and excludes commissions, as described in the methodology. Nothing here is financial advice.