Project mutual fund growth with expense ratio drag. Compare low-cost index funds vs actively managed funds over decades.
A mutual fund calculator projects the future value of an investment in a mutual fund, factoring in the expense ratio (annual fee charged by the fund) which reduces the investor's net return. Even small expense ratios compound dramatically over long horizons — a 0.5% difference in fees over 30 years can mean tens of thousands of dollars in lost returns. Our mutual fund calculator takes the initial investment, annual contribution, gross return, expense ratio, and time horizon, then projects both the gross and net balances year-by-year so you can see the true cost of fund fees.
$6,000 ≈ max annual IRA contribution
S&P 500 historical: ~10%
Index funds: 0.03-0.20%; active: 0.5-1.5%
$190,000
7.50%
$780,326
$707,946
$72,380
9.3% of gross final value lost to fees
| Year | With gross return | After fees | Lost to fees |
|---|---|---|---|
| Year 1 | $16,800 | $16,750 | $50 |
| Year 2 | $24,144 | $24,006 | $138 |
| Year 3 | $32,076 | $31,807 | $269 |
| Year 4 | $40,642 | $40,192 | $449 |
| Year 5 | $49,893 | $49,207 | $686 |
| Year 10 | $108,509 | $105,493 | $3,016 |
| Year 15 | $194,634 | $186,299 | $8,335 |
| Year 20 | $321,181 | $302,307 | $18,875 |
| Year 25 | $507,120 | $468,851 | $38,270 |
| Year 30 | $780,326 | $707,946 | $72,380 |
Even a small expense ratio (0.5-1%) compounds dramatically over decades. On a 30-year horizon, the difference between a low-cost index fund (0.05%) and an average actively managed fund (1%) can exceed $100,000 on a $10k initial + $6k/year contribution. Our mutual fund calculator lets you compare scenarios side by side.
Cross-checked against authoritative formulas (IRS, NIST, ACSM) and updated for 2025/2026 tax years and rates.
No server roundtrip. All math runs in your browser so results appear the moment you finish typing.
We never collect, store, or transmit your inputs. Every calculation runs locally in your browser.
Each calculator includes the formula, plain-English explanation, and FAQs so you understand the result.
Estimates only. Calculator results are for educational and planning purposes — not professional advice. For binding decisions on taxes, investments, health, or legal matters, consult a qualified professional.
FAQ
Everything you need to know about this calculator. Can't find what you're looking for? Email our team.
A mutual fund calculator is a free investment planning tool that projects the future value of an investment in a mutual fund, factoring in the expense ratio (annual fee). Our mutual fund calculator takes initial investment, annual contribution, gross annual return, expense ratio, and time horizon, then projects both the gross and net balances year by year. The output shows the lifetime cost of fund fees — the gap between the gross and net values, which can be substantial over decades.
How it works
Our mutual fund calculator projects both gross and net (after fees) future values year by year, showing the lifetime cost of fund fees.
Type the initial amount and how much you'll add each year. A common starting point is $10k initial + $6k/year (max annual IRA contribution).
Type the gross annual return you expect from the fund (S&P 500 historical average is ~10%; conservative 7-8%). Then enter the fund's expense ratio — the annual fee deducted before you receive returns. Index funds run 0.03-0.20%; active funds run 0.5-1.5%.
Type how many years you'll let the investment grow. 30 years is typical for retirement planning; 10-15 years for shorter goals.
The mutual fund calculator shows the final balance with and without fees, the lifetime cost of fees in dollars and as a percentage of gross value, and a year-by-year table. Compare scenarios by adjusting the expense ratio to see how low-cost index funds stack up against actively managed funds.
Average annual return of major mutual fund categories over the 20-year period ending 2025:
| Fund category | 1-year return | 5-year avg | 10-year avg | 20-year avg |
|---|---|---|---|---|
| S&P 500 Index | ~26% | 14.5% | 12.5% | 10.5% |
| Total Bond Index | ~3% | 0.5% | 1.5% | 3.0% |
| International Index | ~13% | 7.0% | 5.5% | 6.0% |
| Balanced 60/40 | ~16% | 8.5% | 8.0% | 7.5% |
Past returns don't predict future performance. Expense ratios (0.03-1.5%) reduce returns. Use the calculator above with your specific fund, time horizon, and contribution schedule.