Estimate Time5 min

What is an expense ratio?

Key takeaways

  • An expense ratio (ER) is the fee paid to service providers for operating a mutual fund or exchange-traded fund (ETF).
  • When deciding on an investment, it can be helpful to compare that fund's expense ratio to the average for that asset class and to similar funds.

Expense ratios (ERs) may not be on your radar when you're investing in ETFs or mutual funds—but they should be. That's because fund expense ratios can have a meaningful impact on your long-term returns. Learn why with this breakdown on expense ratios.

Fidelity Smart Money

Feed your brain. Fund your future.


What is an expense ratio?

An expense ratio is a fee investors pay to the service providers of their mutual fund or exchange-traded fund that covers management, administrative, custodial, marketing, legal, and accounting costs, among other costs. It's basically the cost to ride. You'll typically see an expense ratio as a percentage of your overall investment in that fund. For example, say a fund charges a 0.50% ER. That means you'll pay $5 annually for every $1,000 invested in that fund. An expense ratio can also be shown in a fund's prospectus as a dollar amount based on a hypothetical $10,000 initial investment.

When researching a fund's expense ratio, you may see two different percentages: a gross expense ratio and a net expense ratio. The gross expense ratio is the total annual fund or class operating expenses (before waivers or reimbursements) paid by the fund and stated as a percent of the fund's total net assets. The net expense ratio takes the gross ratio and removes any discounts or waived fees and/or expense reimbursements that may apply.

How does an expense ratio work?

Funds typically pay regular operating expenses out of fund assets, rather than charge investors separately. These fees include costs associated with portfolio management (paying the team buying and selling investments that make up the fund), marketing, administration, accounting, and reporting.

You won't see a deduction of cash or shares from your brokerage account to pay these fees. Instead, they're automatically taken out of the fund's net assets. Fees are factored into the daily net asset value (NAV), which is the price per share of the fund, and expenses are factored into the returns of the fund.

Why is an expense ratio important?

An expense ratio is important because this ongoing cost represents the portion of your investment's value you won't get to keep. Just as your investment returns may compound over time, so can investment fees. Although you might not notice a total expense ratio's impact on your returns in a single year, over decades of investing, a high expense ratio can eat away at your profits.

Here's a hypothetical example: Let's say there are two investors who each bought $25,000 of two similar funds with different expense ratios, at 0.15% and 0.4% respectively. Over 10 years, let's assume the expense ratios of these funds remain the same, and that each fund grows 5% annually prior to expenses factored in (aka net of fees). Rounded to the nearest dollar, these values would be the following:

Line graph showing the hypothetical investment growth with different expense ratios.
Investor 1 (0.15% expense ratio) Investor 2 (0.4% expense ratio)
Year Value at beginning of year Year Value at beginning of year
0 $25,000 0 $25,000
1 $26,211 1 $26,145
2 $27,480 2 $27,342
3 $28,811 3 $28,595
4 $30,206 4 $29,904
5 $31,668 5 $31,274
6 $33,202 6 $32,706
7 $34,810 7 $34,204
8 $36,495 8 $35,771
9 $38,263 9 $37,409
10 $40,116 10 $39,122
10-year cumulative return 60.5% 10-year cumulative return 56%
This hypothetical illustration, which assumes an annual 5% return net of fees over 10 years, is for illustrative purposes only and does not represent actual or future performance of any investment option.
As you can see in this example, a slightly higher expense ratio can reduce your returns over time. Just a 0.25 percentage point difference in expense ratio could make a 4.5 percentage point difference in total return after 10 years.

Expense ratios for different types of funds

Expense ratios can vary depending on how the fund is managed (actively or passively) and how it's structured (as an ETF or a mutual fund).

Active vs. passive fund expense ratios

A primary influence of a fund's expense ratio is the fund's management style. Actively managed funds have a team of financial professionals conducting research to inform their investment decisions. For that extra work, they typically charge a higher management fee (which is a component of the expense ratio) than passively managed funds. Passive funds generally instead use technology in an attempt to mirror the performance of an area of the market.

ETF expense ratios

ETFs can be either actively or passively managed, and their expense ratios typically reflect that. A good number of ETFs are passively managed index funds. For example, this means they aim to replicate the performance of a group of stocks, like the S&P 500®, which tracks the performance of about 500 of the largest companies in the US. A rising number of ETFs use more active strategies and may have higher expense ratios to match.

Mutual fund expense ratios

Because historically many mutual funds are actively managed and many ETFs were historically passively managed, you may see higher expense ratios, on average, in mutual funds. That higher expense ratio helps pay for the professional expertise that goes into selecting investments. However, there are also mutual funds that seek to track the performance of an index and have comparable or lower expense ratios than their ETF counterparts.

Expense ratio formula

The formula to determine an expense ratio is simple, though you won't have to do the math yourself. All funds are required by law to disclose their expense ratios. Still, here's the expense ratio formula:

Expense ratio (%) = Total fund operating costs / Fund average net assets

What is an average expense ratio?

Knowing average expense ratios could be helpful context when researching funds. In 2024, the average expense ratio for equity mutual funds was 0.40%; for bond mutual funds, it was 0.38%.1 Among ETFs, the average expense ratio in 2024 was 0.14% for equity ETFs and 0.10% for bond ETFs.2 You could compare a fund's total expense ratio to similar funds with similar goals for more specific comparisons.

It's important to remember that a fund's expense ratio is just a single factor to consider when choosing an investment option. Remember to also consider a fund's investment objectives, strategy, and risks. Make sure to contextualize the investment with your risk tolerance and time horizon, and don't hesitate to contact an investment professional to discuss what investment options may be appropriate for your financial situation.

How to research expense ratios

Whether an expense ratio makes sense for you depends on your investment goals, whether you pick an actively or passively managed ETF or mutual fund, and how that number measures up to similar funds' expense ratios. If you're curious how to research total expense ratios at Fidelity, here's a step-by-step guide:

  1. Use the right tool: You can research different funds' expense ratios in our Mutual Funds Research tool or ETF screenerLog In Required at Fidelity. 
  2. Narrow your search: You could filter by asset classes you want in your fund (like bonds and stocks, which are called equities in the tools), the management approach you want (called passive index or active in the tools), and issuer, like Fidelity.
  3. Compare expense ratios: With a handful of similar funds selected, look at each option's fund overview. On the ETF screener, you'll see net expense ratios on the “Search Criteria” tab. On the Mutual Funds Research tool, you'll see net and gross expense ratios if you scroll to the right on the “Overview” tab.

Search Fidelity funds

Find investment options to meet your goals.

More to explore

1. "Trends in the Expenses and Fees of Funds, 2024," Investment Company Institute, March 2025. 2. "Trends in the Expenses and Fees of Funds, 2024," Investment Company Institute, March 2025.

Investing involves risk, including risk of loss.

Past performance is no guarantee of future results.

Investment decisions should be based on an individual's own goals, time horizon, and tolerance for risk. Indexes are unmanaged. It is not possible to invest directly in an index. The S&P 500® Index is a market capitalization-weighted index of 500 common stocks chosen for market size, liquidity, and industry group representation to represent US equity performance.

Views expressed are as of the date indicated, based on the information available at that time, and may change based on market or other conditions. Unless otherwise noted, the opinions provided are those of the speaker or author and not necessarily those of Fidelity Investments or its affiliates. Fidelity does not assume any duty to update any of the information.

Fidelity does not provide legal or tax advice. The information herein is general and educational in nature and should not be considered legal or tax advice. Tax laws and regulations are complex and subject to change, which can materially impact investment results. Fidelity cannot guarantee that the information herein is accurate, complete, or timely. Fidelity makes no warranties with regard to such information or results obtained by its use, and disclaims any liability arising out of your use of, or any tax position taken in reliance on, such information. Consult an attorney or tax professional regarding your specific situation.

The Fidelity Investments and pyramid design logo is a registered service mark of FMR LLC. The third-party trademarks and service marks appearing herein are the property of their respective owners.

Fidelity Brokerage Services LLC, Member NYSE, SIPC, 900 Salem Street, Smithfield, RI 02917

© 2025 FMR LLC. All rights reserved. 1217619.1.0