TL;DR: An expense ratio is the annual fee a fund takes from its assets, expressed as a percentage. Illustrative example only: on a $10,000 holding, a 0.60 percent expense ratio costs $60 a year, since $10,000 multiplied by 0.006 equals $60, while a 0.05 percent ratio costs $5, since $10,000 multiplied by 0.0005 equals $5. The difference is $55 a year on that holding, since $60 minus $5 equals $55, before any compounding of the savings.
Key Takeaways
- The worked example in this draft is fully illustrative. Its arithmetic is recorded in Sources and method below and was recomputed for this draft.
- Definitions here follow standard filing usage. Where providers or filings use a different definition, the draft says so and tells you to check which one a source is using.
- This is educational information, not financial advice, and it is not a recommendation to buy, sell, or hold any security or fund.
Convert the percentage into dollars
All figures in this section are illustrative. Expense ratios are quoted in percentages small enough to look trivial, so convert them. The fee is not billed to you directly. It is deducted inside the fund, reducing the return you see. On $10,000, the 0.60 percent fund takes $60 in a year and the 0.05 percent fund takes $5. Scale the holding to $100,000 and the same comparison is $600 against $50. The percentage did not change. The dollars did, which is why the ratio matters more as a portfolio grows.
The ratio covers the fund running costs, such as management, administration, and custody. It does not cover your broker commissions, bid ask spreads when trading fund shares, or any advice fee you pay separately. Fund documents state the ratio and what it includes. For the fund types it most often decides between, see what is an ETF and what is an index fund, where low cost is a core part of the proposition.
Why the gap compounds
A fee is not a one year event. Money taken in fees cannot compound for you afterwards, so a yearly gap repeats and grows with the portfolio. You do not need a compound interest table to see the direction: $55 saved in year one stays invested, and the saving repeats on a larger balance in later years if the holding grows. What is compound interest shows the underlying mechanism. The honest limit is that fees are only one input. A cheap fund tracking the wrong index for your purpose is not a bargain, and a more expensive fund is not automatically worse if what it holds is genuinely different. Cost comparisons are fairest between funds holding substantially the same assets.
Also note that the ratio can change. Funds raise and lower fees, and the figure in the current prospectus or factsheet, not a review from years ago, is the one that applies to you now.
How to use the ratio when choosing
Start with purpose, then holdings, then cost. First decide what exposure you want. Then list funds that provide it. Then use the expense ratio to choose among near identical options, where it is often the most reliable differentiator available, because future performance is uncertain and the fee is contractual. Check also for minimum investments and any platform charges that sit outside the ratio.
Investors tracking funds alongside shares in one place, the habit behind track investments across multiple brokerages, should record the ratio for each fund holding. A portfolio level weighted cost figure, built from those ratios and holding sizes, is a clearer number to monitor year to year than any single fund fee.
Fees reduce what a holding actually delivers over time, the combined figure measured in total return explained. This article is educational information, not financial advice. Prices, company figures, and fund figures in the worked example are illustrative and are not figures for any real security, company, or fund.
Sources and method
- Target keyword: "expense ratio explained" from .saeo/keywords.yaml (queue entry added 2026-10-31). No search volume or difficulty figure is claimed; both are recorded as unknown in the queue entry.
- All figures are labelled illustrative examples. Arithmetic verified for this draft on 2026-10-31 by recomputation in Python: 10,000 multiplied by 0.006 equals 60; 10,000 multiplied by 0.0005 equals 5; 60 minus 5 equals 55.
- Internal links checked against existing drafts in this folder on 2026-10-31: what-is-an-etf, what-is-an-index-fund, what-is-compound-interest, track-investments-across-multiple-brokerages.
- Distinction check: ETF and index fund explainers exist. No explainer covered the expense ratio cost itself.
