An expense ratio is the slice of a fund's assets that its manager keeps every year to cover management, administration and marketing, deducted quietly from the fund's returns rather than billed to you directly. This calculator turns that percentage into cash: what it costs you this year, and what ten years of the same charge adds up to on today's balance.
What counts as a cheap or an expensive fund
A broad US index fund now typically charges somewhere between 0.03% and 0.10%, an actively managed stock fund is commonly priced between 0.50% and 1.00%, and a specialist or sector fund can run 1.00% or higher. Anything above roughly 1% needs a strong performance case to justify the drag, because that gap compounds against you every single year the fund is held.
Bond funds usually sit below equity funds of the same style, since there is less active research involved in holding a basket of debt instruments. A bond index fund above 0.30% is worth questioning against cheaper alternatives tracking the same benchmark.
The number itself only measures the ongoing charge. It excludes trading costs, bid-ask spreads and any separate advisory or platform fee your broker adds on top, so the true annual drag on your account is frequently higher than the expense ratio alone suggests.
Two funds, one decision: a side-by-side example
Take a 50,000 balance sitting in an actively managed fund charging 1.10%. That works out to 550 a year, or roughly 45.83 a month, and 5,500 if the balance and the charge both stayed flat for ten years.
Move the same 50,000 into an index fund tracking a similar market at 0.20% and the yearly cost drops to 100, or about 8.33 a month, with a ten-year running total of 1,000. Switching funds alone, with no change in what you are invested in, frees up 450 a year.
A larger account magnifies the same gap. A 250,000 portfolio charged at 0.75% costs 1,875 a year, or 156.25 a month, and 18,750 over a flat ten-year run. Halving that rate to 0.375% would cut the annual charge to 937.50, showing why the fee comparison matters more, in absolute terms, the bigger the balance gets.
Where the flat ten-year figure understates the real cost
The ten-year total here is a simple multiplication: this year's charge times ten, on a balance that is assumed to stay the same size. Real accounts grow, and a fee taken from a growing balance compounds against you rather than staying level, so the true cost over a decade is usually higher than this shortcut implies.
To see the difference, take that same 75,000 balance growing at 7% a year before fees. At a 0.10% expense ratio the net return is 6.90%, and the balance reaches roughly 146,000 after ten years. At a 0.90% expense ratio the net return falls to 6.10%, and the same starting balance reaches roughly 135,600. The 0.80 percentage-point fee gap costs about 10,400 over that decade, more than double the 6,000 you would get by simply multiplying the fee by the starting balance and by ten.
The gap widens further the longer money stays invested, because each year's fee is taken from a balance that is larger than the year before purely as a result of past growth. A fee difference that looks trivial on a single year's statement becomes one of the largest costs in a retirement account held for thirty years.
Where this calculation stops being reliable
It assumes the expense ratio published today stays fixed. Fund providers change pricing, sometimes lowering it to compete or raising it after a share class conversion, so a ten-year projection is really a snapshot rather than a promise.
It also treats the fund balance as static, ignoring new contributions, withdrawals, and market growth or decline. Anyone adding money regularly, or drawing an income in retirement, will see a different total cost than the flat projection shown here, usually higher for a growing account and lower for a shrinking one.
It cannot see costs that sit outside the expense ratio: trading commissions inside the fund, the spread between a fund's price and its underlying assets, front-end or back-end sales loads on some mutual fund share classes, and any percentage fee charged separately by a financial adviser or brokerage platform.
Jurisdiction and disclosure differences
In the United States, the expense ratio is disclosed in the fund's prospectus fee table and its total is called the total annual fund operating expenses, a figure the SEC requires every mutual fund and ETF to publish and update annually.
In the UK and EU, the equivalent figure is usually labelled the ongoing charges figure, or OCF, and is disclosed in the Key Investor Information Document; it is built the same way but the label and some included cost categories differ slightly from the US expense ratio, so do not assume the two numbers are always calculated identically fund to fund.
401(k) and workplace pension platforms sometimes layer an additional administration fee on top of the underlying fund's expense ratio. Check the plan's own fee disclosure alongside this calculator's figure, since the number quoted by your employer's provider may already include, or may separately add, that extra charge.
Frequently asked questions
- What is a good expense ratio for an index fund?
- Broad US and international index funds are commonly available between 0.03% and 0.10% today. Anything meaningfully above that for a fund tracking a standard, well-known benchmark is worth comparing against cheaper alternatives that hold the same or a very similar basket of assets.
- Is 0.5% expense ratio high?
- It is high relative to index fund pricing, which often sits below 0.10%, but it is on the lower end for an actively managed fund, where 0.50% to 1.00% is typical. Whether it is worth paying depends on whether the fund's strategy and track record justify roughly five to ten times the cost of a comparable index option.
- How does the expense ratio actually get taken out of my account?
- It is not billed as a separate line item. The fund deducts a daily pro-rata share of the annual percentage from the fund's assets before calculating the price you see, so your account balance already reflects the charge and no transaction ever appears on your statement for it.
- Does a higher expense ratio mean better fund performance?
- Not on its own. A higher charge pays for active management, research or a specialist strategy, but plenty of expensive funds underperform cheaper index alternatives after fees over long periods. The expense ratio is a cost you know in advance; the extra return it might buy is not guaranteed.
- Why does a small percentage difference matter so much over time?
- Because the fee is taken from a balance that compounds. A 0.80 percentage-point gap on a 75,000 balance growing at 7% a year costs roughly 10,400 over ten years once compounding is included, noticeably more than simply multiplying the fee by the starting balance would suggest.
- Do ETFs have expense ratios too, and are they lower than mutual funds?
- Yes, ETFs disclose an expense ratio the same way mutual funds do, and as a category they tend to run cheaper on average because most are built to track an index rather than pick investments actively. Always check the specific fund's own figure rather than assuming every ETF is inexpensive, since leveraged and specialist ETFs often charge well above 1%.
Sources
- SEC Investor.gov — Mutual Fund and ETF Fees and Expenses — Explains how the expense ratio is disclosed in a fund's prospectus fee table and deducted from fund assets (bulletin dated July 23, 2025).
- Investment Company Institute — Trends in the Expenses and Fees of Funds, 2024 — Reports the 2024 asset-weighted average expense ratio for US equity and bond mutual funds and its long-term decline (published March 2025).