This mutual fund calculator projects how your investment grows with regular monthly contributions, and shows exactly how much the fund’s expense ratio and any sales charge cost you over time compared with a low-cost fund.
How fees affect your returns
A mutual fund’s expense ratio is taken from the fund’s assets every year, so it lowers your return. A sales charge (front-end load) is taken from each purchase before it is invested. Because these costs compound, a seemingly small difference can grow large over decades.
The calculator applies your return and the expense ratio each year: growth factor = (1 + return) × (1 − expense ratio).
Worked example
Investing $10,000 up front plus $200 a month for 20 years at a 7% return before fees grows to about $130,550 in a fund with a 0.5% expense ratio. The same plan in a 0.05% index fund would reach about $139,200, roughly $8,650 more.
Common mutual fund costs
| Cost | What it is |
|---|---|
| Expense ratio | Yearly operating cost as a % of assets |
| Front-end load | Sales charge taken when you buy |
| Back-end load | Charge when you sell, often falling over time |
| 12b-1 fee | Marketing and distribution fee, included in the expense ratio |
How to keep costs low
- Compare expense ratios; broad index funds are often among the cheapest.
- Look for no-load funds, or ask about breakpoint discounts on larger purchases of load funds.
- Check the fund prospectus fee table before you invest.
Frequently asked questions
What is a good expense ratio?
Lower is better. Many broad index funds charge under 0.1% a year, while actively managed funds often charge 0.5% to 1% or more.
How are mutual fund returns calculated?
Returns include price changes plus reinvested dividends and capital gains, after the fund’s expenses. Past returns do not guarantee future results.
What is the difference between a mutual fund and an ETF?
Both hold baskets of investments. ETFs trade on an exchange during the day like stocks and are often cheaper and more tax-efficient; mutual funds are bought and sold once a day at their closing value.
Are mutual fund fees tax-deductible?
No. The expense ratio is taken inside the fund and simply reduces your return.
Where can I find a fund’s fees?
In the fee table at the front of the fund’s prospectus, or on its fact sheet. FINRA’s Fund Analyzer can compare funds.
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Sources
Last reviewed: October 2026. This calculator is for education only and is not financial, tax or legal advice.