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Mutual Fund & Investment Calculator

$
yr
%

Total value

$104,793

Expected return: 7%
Amount invested
$48,000
Estimated returns
$56,793
Total value
$104,793

Growth over time

120
Amount investedEstimated returns

Estimates only. Returns are not guaranteed; past performance does not predict future results.

How this mutual fund calculator works

This free mutual fund and investment calculator projects how your money could grow through a mutual fund, index fund or ETF. Enter a one-time lump sum, a monthly contribution (dollar-cost averaging), or both, choose an expected annual return and a time horizon, and the calculator compounds your money month by month. Unlike most US calculators, it also shows your return after fees and after tax across a taxable brokerage, Roth IRA or traditional 401(k) — and lets you adjust for inflation.

Using each mode

  • Monthly (SIP / dollar-cost averaging): enter how much you invest each month. The calculator adds each contribution and compounds the balance.
  • Lump sum: model a single upfront investment growing over time.
  • Step-up: increase your monthly contribution by a set percentage each year — useful as your income rises.
  • Withdrawal (SWP): start from a balance and draw a fixed monthly income; see how long the money lasts.
  • Goal: enter a target (e.g. $1,000,000) and solve for the monthly amount, lump sum, time or return needed.

Toggle inflation-adjusted, expense-ratio impact, after-tax and the conservative/expected/aggressive scenario band to pressure-test your plan.

What return should I assume?

The long-run average annual return of the US stock market (S&P 500) has been roughly 10% nominal / ~7% after inflation over the past century. A diversified stock fund is often modeled at 7–10%, a balanced fund at 5–7%, and bonds lower. These are long-term averages — real returns vary widely year to year. The calculator defaults to 7% and offers a scenario range so you can see a realistic spread rather than a single guess.

How mutual funds are taxed in the US

In a taxable brokerage account, long-term capital gains (assets held over one year) are taxed at 0%, 15% or 20% depending on income; short-term gains are taxed as ordinary income. Qualified dividends get the long-term rate. In a Roth IRA, qualified growth and withdrawals are entirely tax-free. In a traditional 401(k) or IRA, contributions are pre-tax and grow tax-deferred, with withdrawals taxed as ordinary income. See IRS Topic No. 409 (Capital Gains and Losses) and IRS Publication 550 for the official rules. The 2025 401(k) employee contribution limit is $23,500 ($31,000 with the 50+ catch-up).

How expense ratios eat into returns

A fund's expense ratio (TER) is deducted from returns every year. It looks tiny but compounds: on a $100,000 portfolio over 30 years at 7%, a 1.0% expense ratio instead of 0.05% can cost well over $150,000 in lost growth. Turn on expense-ratio impact to see your net-of-fees result — index funds and ETFs typically charge 0.03%–0.20%, while many active mutual funds charge 0.5%–1.5%.

Accounts and wrappers to consider

Tax-advantaged accounts dramatically change outcomes. Max out tax-advantaged space first: a Roth IRA (tax-free growth), an employer 401(k) (especially up to any match), and an HSA if eligible. A taxable brokerage is fully flexible but gains and dividends are taxed. The calculator's account toggle lets you compare keeping the same fund in a taxable account versus a Roth or 401(k).

What is the difference between a mutual fund calculator and a compound interest calculator?⌄
A compound interest calculator shows how a balance grows at a fixed rate. A mutual fund calculator does the same compounding but is built for investing: it handles monthly contributions (dollar-cost averaging), lump sums, expense ratios (fund fees), inflation, and the capital-gains tax treatment of taxable, Roth and 401(k) accounts.
How do I calculate dollar-cost averaging returns?⌄
Use the Monthly (SIP) mode: enter your monthly contribution, the expected annual return and the number of years. The calculator invests each month and compounds the balance, then shows total invested versus estimated returns. Dollar-cost averaging spreads your entry over time, reducing the impact of buying everything at a market peak.
Is a Roth IRA or a taxable account better for mutual funds?⌄
A Roth IRA is usually better for long-term growth because qualified withdrawals are completely tax-free, so you keep 100% of the gains. A taxable brokerage account is taxed on dividends and capital gains but has no contribution limits or withdrawal restrictions. Use the after-tax toggle and switch the account type to compare the two on identical inputs.
How much does the expense ratio matter?⌄
A lot over time. Because the fee is charged every year on the whole balance, a 1% expense ratio versus 0.05% can reduce a 30-year result by six figures on a large portfolio. Lower-cost index funds and ETFs keep more of the market return in your pocket.
What is the long-term capital gains tax rate on mutual funds?⌄
For assets held more than one year, long-term capital gains are taxed at 0%, 15% or 20% depending on your taxable income. Assets held one year or less are taxed at your ordinary income rate. See IRS Topic No. 409 for current brackets.
How much do I need to invest to reach $1 million?⌄
Use Goal mode and set the target to $1,000,000. Choose what to solve for — required monthly investment, lump sum, time, or return — and the calculator works backward. For example, at a 7% return, investing about $1,920 a month for 20 years reaches roughly $1 million.