Expense Ratios: What a Fund's Fee Costs You Over 30 Years

What an expense ratio pays for, how it comes out of your balance without a bill, and a worked 30-year example showing what different fee levels cost.

Published by Greg M., Editor in Chief · Updated November 9, 2026

A fund’s expense ratio is a small number, often well under 1%, and it never shows up as a bill. That’s exactly why it’s easy to ignore. Over a few decades it can take a surprisingly large share of what your money would otherwise have grown to.

This guide explains what the expense ratio is, where to find it, and how to put a dollar figure on it for your own time horizon. All figures in the worked examples are invented, and the return is an assumption chosen to show the arithmetic, not a forecast.

What the expense ratio is

Running a fund costs money: the adviser who manages the portfolio, the custodian holding the assets, accountants, lawyers, transfer agents and, in some mutual funds, marketing. The fund pays these annual operating expenses out of its own assets. Its total, expressed as a percentage of the fund’s average net assets, is the expense ratio, and the prospectus fee table shows it as “Total Annual Fund Operating Expenses” (Investor.gov, Mutual Fund and ETF Fees and Expenses, checked November 9, 2026).

It’s usually made up of three lines:

• Management fees, paid to the fund’s investment adviser.
• Distribution and/or service (12b-1) fees, which pay for marketing and selling the fund. These typically apply to mutual funds, not ETFs.
• Other expenses, such as custody, legal, accounting and transfer-agent costs.

A fund that invests in other funds also shows “acquired fund fees and expenses”, the costs of the underlying funds that you pay indirectly.

How you pay it without seeing it

Because the fund pays its expenses from fund assets, the value of every investor’s shares falls by that amount. You pay it whether the fund goes up or down that year. Nothing is deducted from your account as a separate line; the fee is already reflected in the fund’s share price and in the returns it reports.

In practice, a 0.50% expense ratio means roughly $5 a year for every $1,000 you have in the fund. That sounds trivial, and in any one year it is. The cost comes from repetition: the fee is charged every year on a balance that is, you hope, growing, and every dollar paid in fees is a dollar that no longer compounds.

A 30-year worked example

Here is an invented example to show the mechanics. Three hypothetical funds hold identical portfolios and earn the same assumed 6% a year before fees. The only difference is the expense ratio: 0.05%, 0.50% or 1.00%. An investor puts in $10,000 once and leaves it alone for 30 years.

The calculation uses the same convention as our fee calculator: each year the balance grows by 6%, then the fee is taken as a percentage of the grown balance. So the yearly growth factor is 1.06 × (1 − fee).

After 30 years the 1.00% fund ends $14,095 behind the 0.05% fund, and the 0.50% fund ends $7,164 behind. Two things stand out.

The gap is bigger than the fees. In the 1.00% fund, the fees themselves add up to $6,970, yet the shortfall is $14,095. The rest is growth that money would have earned if it had stayed invested.

The gap widens with time. Between the 0.05% and 1.00% funds it’s $1,623 after 10 years, $5,521 after 20 and $14,095 after 30. Measured against a fund with no fee at all ($57,435 after 30 years), the 1.00% fund gives up about 26% of the ending value and the 0.05% fund about 1.5%.

With yearly contributions

Most people add money over time. In a second invented example, the same investor starts with $10,000 and adds $5,000 at the end of each year for 30 years, contributing $160,000 in total, again assuming 6% before fees.

Here the difference between 0.05% and 1.00% is $76,926, almost half of everything contributed. Larger balances mean larger fees in dollars, even at the same percentage.

What this example leaves out

Real funds don’t earn a steady 6%; returns vary from year to year and can be negative, and nobody knows what any fund will return. Funds also deduct expenses gradually from assets rather than in one yearly charge, so real figures will differ slightly. Taxes, trading costs and any sales loads or advisory fees are ignored. And a lower fee doesn’t guarantee a better result: two funds with different strategies will earn different returns before fees. The comparison is cleanest when, as here, the funds hold the same thing.

The SEC’s own illustration makes the same point with different numbers: $100,000 growing at an assumed 4% a year for 20 years ends at roughly $208,000 with a 0.25% annual fee, $198,000 with 0.50% and $179,000 with 1.00% (Investor.gov, How Fees and Expenses Affect Your Investment Portfolio, checked November 9, 2026). To try your own balance, contributions, time horizon and two fee levels, use the fee calculator.

Where to find a fund’s expense ratio

Every mutual fund and ETF prospectus must include a standardized fee table, with the expense ratio near the top of the summary section. The same table includes a hypothetical example showing the dollar cost of a $10,000 investment over 1, 3, 5 and 10 years, which is a quick way to compare funds in dollars (Investor.gov, How to Read a Mutual Fund Prospectus, Part 2, checked November 9, 2026). Reading a fund prospectus fee table walks through a real one line by line.

Fund websites, fact sheets and brokerage screens also show expense ratios. FINRA’s free Fund Analyzer (checked November 9, 2026) lets you compare the costs and projected account values of up to three mutual funds, ETFs or share classes side by side.

Things that can make the headline figure misleading

Fee waivers. Some fee tables show a “fee waiver and/or expense reimbursement” line, where the adviser has agreed to cut its fees, temporarily or indefinitely. The figure after the waiver can be lower than the fund’s underlying costs, and the SEC notes that waived fees may be recouped later. The footnotes to the table are the place to look for how long a waiver is expected to last.

Share classes. One mutual fund can offer several share classes with different expense ratios for the same portfolio. The figure that matters is the one for the class actually being bought.

Costs outside the ratio. The expense ratio doesn’t include the fund’s own trading costs, sales loads, redemption or account fees, brokerage commissions, ETF bid-ask spreads, or any advisory fee you pay on top. The SEC also warns that with funds that call themselves no-expense or zero-expense, or emphasize low expense ratios, others may collect fees for sales or distribution, which investors then pay separately, for example as broker commissions or wrap-fee program fees (Investor.gov, Mutual Fund and ETF Fees and Expenses, checked November 9, 2026). Those costs are covered in loads, 12b-1 fees and advisory fees.

How people use the number

The SEC’s framing is a useful one: a fund with higher costs has to perform better than a lower-cost fund just to give you the same return. Fees are one of the few things about a fund that are known in advance, whereas future returns are not.

People comparing funds often look at the expense ratio alongside what the fund holds and how it’s managed. For index funds that track the same or similar indexes, the portfolios may be close enough that cost is one of the main remaining differences, though tracking error and trading costs still vary. For actively managed funds, the question is whether the strategy is worth its extra cost, which no fee table can answer.

None of this tells you which fund to choose. It does let you see, in dollars, what a given fee level would cost over your own time horizon under an assumption you set yourself.

Common questions

Is the expense ratio charged once a year? Funds deduct operating expenses from fund assets on an ongoing basis, and the expense ratio expresses the yearly total as a percentage. You don’t receive a bill; the cost is reflected in the share price.

Does a 1% fee cost me 1% of my money? Each year, roughly. Over long periods it costs more than that adds up to, because the fees also remove the growth that money would have earned. In the 30-year invented example above, a 1.00% fee left about 26% less than a fund with no fee.

Do ETFs have expense ratios? Yes. ETFs pay management fees and other operating expenses out of fund assets, just like mutual funds, and their prospectus fee table shows the total.

What’s the difference between a gross and a net expense ratio? The gross figure is the fund’s total operating expenses; the net figure is after any fee waiver or expense reimbursement the adviser has agreed to. When a waiver applies, the fee table shows it as a separate line; check the footnotes for how long it’s expected to last.

Does a lower expense ratio mean a better fund? Not on its own. It means lower known costs. Returns before fees, risks and what the fund holds still differ, and past performance does not guarantee future results.

Sources checked November 9, 2026: Investor.gov (SEC Office of Investor Education and Assistance) Mutual Fund and ETF Fees and Expenses (July 23, 2025), How Fees and Expenses Affect Your Investment Portfolio (July 23, 2025) and How to Read a Mutual Fund Prospectus, Part 2 (June 13, 2016); FINRA Using the FINRA Fund Analyzer.