What do your fund's fees really cost you?
A free calculator for anyone with a 401(k), an IRA or a brokerage account. Put in your balance and your fund's fees. See what they add up to over the years, including the growth you lose on the money fees take.
Compare the fees
Type in your numbers. We grow the same money at the same return in two funds. The only thing that is different is the fees.
What the fees cost you
Where the difference comes from
Fees cost you twice: the money taken out, and the growth that money would have earned if it had stayed in. We show both.
| Your fund | Index fund | Difference | |
|---|---|---|---|
| Fees paid | - | - | - |
| Growth lost on those fees | - | - | - |
| Total cost of fees | - | - | - |
With no fees at all, the money would grow to - from - put in. Total cost of fees = that amount minus what each fund ends with. Figures are rounded to the nearest dollar, so a total can be $1 off from its parts.
"Your gains" means what the money would have earned with no fees. The share counts fees paid plus the growth lost on them.
The two balances, year by year
See the balances as a table
| Year | Index fund | Your fund | Gap |
|---|
How we calculate
We work it out one year at a time, the same way for both funds. Each year:
- The starting balance goes in at the start of year 1. A sales charge is taken from it too.
- Growth is added once a year (yearly compounding). The return is the same every year.
- Fees paid = every sales charge + every yearly fee + every performance fee.
- With no fees: the same money and the same return, with nothing taken out.
- Total cost of fees = the no-fee balance minus the fund's ending balance. Growth lost on fees = total cost minus fees paid.
- The difference between the funds = the index fund's ending balance minus your fund's. It always equals the difference in fees paid plus the difference in growth lost.
- Share of gains that went to fees = total cost of fees / (no-fee balance minus everything you put in).
- We leave out taxes, trading costs inside a fund, inflation and ups and downs in returns. Real fees are often taken a little at a time during the year, not once at the end, so real results can differ a little.
Check our math against the SEC's example
The SEC shows "a $100,000 investment that grows 4% annually over 20 years" at three fee levels (Investor.gov, July 23, 2025). Our calculator gives the same answers, rounded the way the SEC rounds them:
| Fee | SEC says | Our calculator |
|---|---|---|
| 0.25% a year | about $208,000 | - |
| 0.50% a year | about $198,000 | - |
| 1.00% a year | about $179,000 | - |
Do higher fees buy better results?
A fund with higher fees has to earn more just to end up even. S&P Dow Jones Indices counts how often actively managed U.S. stock funds do worse than an index (SPIVA U.S. Scorecard, Mid-Year 2026). For periods ending June 30, 2026, this share of all actively managed large-company U.S. stock funds did worse than the S&P 500:
| Over the last | Did worse than the S&P 500 |
|---|---|
| 1 year | 78.69% |
| 3 years | 76.63% |
| 5 years | 89.32% |
| 10 years | 83.33% |
| 15 years | 90.49% |
| 20 years | 92.61% |
Of the 690 large-company funds at the start of the 20 years, 36.52% were still open at the end (SPIVA, Report 2). These figures describe the past and one group of funds. Some funds did beat the index. The report cannot tell you whether your fund will.
What the SEC tells investors
What you can do
- Find your fund's expense ratio. It is in the fund's prospectus fee table and on its fact sheet. A prospectus "contains a standardized table of fees and expenses" (SEC).
- In a 401(k), read the yearly fee notice. Your plan must give you each option's expense ratio "in a chart or similar format that is designed to facilitate a comparison," before you first pick investments and every year after (29 CFR 2550.404a-5). Your quarterly statement shows some fees in dollars, but "does not include charges paid indirectly from your investments" (U.S. Department of Labor). You can ask your plan for the prospectuses.
- Ask your plan what index funds it offers. The yearly fee notice lists every option with its cost, so you can compare.
- Check for a fee on top. If you pay an advisor or a managed account service, that fee is often a % of your balance, charged on top of the funds' own fees. Ask for it in writing.
- Check before you move money. Selling in a regular account, or moving money out of a 401(k) or IRA the wrong way, can bring taxes, penalties or fees. Ask your plan or a tax professional first.
This is general information, not investment, tax or legal advice. We do not recommend any fund or company, and we are not a licensed investment adviser.
Where every number comes from
We read each of these on November 13, 2026. Every figure on this page traces to one of them. Our research log, with a short exact quote for each figure and the places where sources differ, is public: research-log.txt.
Who made this, and how to correct it
General information, not investment, tax or legal advice. The calculator shows what fees cost under the numbers you type. It does not predict returns and does not say what you should buy or sell.
Made by Known Quantity LLC, a small Rhode Island company, as free public-interest work. We have no affiliation with any fund company, broker or adviser, and nobody paid for this page. We do not see or keep anything you type here.
If we got something wrong, email [email protected] with the source and we will fix it.
Free to reuse, copy, print and share, with or without credit. Last updated November 13, 2026.
Know a group that could use a free tool like this?
We build free public-interest pages, tools and spreadsheets for people and small charities. Send a few lines.