Savings Calculators

Investment Return Calculator

Project the future value of an investment with initial deposit, monthly contributions, and compounding returns.

Uses monthly compounding — the same approach mutual fund and brokerage projections use.

Initial balance

Monthly contribution

Annual return

Years

Projected final value

$691,150

After 30 years at 7% annual return with monthly compounding.

Total contributions

$190,000

Interest earned

$501,150

Growth multiple

3.64×

Explain this result

Turn the numbers above into plain-language takeaways. Educational only — not financial advice.

Save & Compare Scenarios

Save the current inputs under a name, then reload or compare them side by side. Scenarios stay on this device only.

Overview

How the Investment Return Calculator Works

Most investing outcomes are decided by three inputs: how much you start with, how much you add each month, and how long you leave it alone. This calculator compounds monthly, the same convention brokerage and fund projections use, so you can see how the contribution schedule and the time horizon trade off against each other. The result that surprises people is how much of the final balance is growth rather than deposits once the horizon passes twenty years.

Formula

The Math Behind the Calculator

Future Value = PV × (1 + r)^n + PMT × ((1 + r)^n − 1) / r, where PV is the initial investment, PMT is the monthly contribution, r is the annual return divided by 12, and n is the number of months. Total contributions = PV + (PMT × n); total growth = FV − total contributions.

Example

A Worked Example

Start with $10,000, add $500 a month, and assume a 7% annual return over 25 years. You contribute $160,000 in total, and the balance reaches roughly $460,000 — about $300,000 of it pure compounding. Shorten the horizon to 15 years and the same $500 a month produces roughly $190,000, with only $90,000 of growth. The extra decade is worth more than doubling the monthly contribution.

How to use

How to Use the Investment Return Calculator

1Enter your starting balance, or zero if you are beginning from scratch.
2Enter the amount you will realistically contribute every month and keep contributing through market downturns.
3Choose an expected annual return; 6–7% is a common long-run assumption for a diversified stock portfolio, 4–5% for a balanced one.
4Set the number of years you will leave the money invested, not the number of years until you first need part of it.
5Compare two scenarios — one with a longer horizon, one with a higher contribution — to see which lever matters more for you.

Interpretation

What the Results Mean

Future value is the projected nominal balance at the end of the period, before tax and before inflation.
Total contributions is the money you actually put in, and the difference between it and future value is compounding at work.
If growth is a small share of the final balance, your horizon is short and contributions are doing most of the work.
Small changes in the assumed return compound dramatically over long horizons, which is why fees of even 1% matter so much.

Keep exploring

Smart Next Steps

What to explore next

Compare Roth vs Traditional IRA tax treatment.Roth vs Traditional
Adjust returns for inflation.Inflation-adjusted

Avoid

Common Mistakes to Avoid

Assuming a double-digit return because of a recent bull market; long-run averages include the bad decades too.
Reading the nominal figure as spending power — inflation will erode a meaningful share of it.
Ignoring expense ratios and advisory fees, which come straight off the return you enter here.
Stopping contributions during a downturn, which removes exactly the cheap purchases that drive later growth.
Forgetting taxes on gains in a regular brokerage account, which reduce the real outcome versus a tax-advantaged one.

Scope

Limitations of This Calculator

Returns are assumed smooth and constant. Real markets deliver sequences of gains and losses, and sequence risk matters greatly near withdrawal.
No tax is applied. Results are appropriate for a tax-deferred account and optimistic for a taxable brokerage account.
No inflation adjustment. Use the inflation-adjusted return calculator to see the figure in today's purchasing power.
Fund fees, advisory fees, trading costs, and bid-ask spreads are not deducted.
It does not model withdrawals, rebalancing, dividend tax drag, or changing contribution amounts over time.

Keep going

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Inflation-Adjusted Return Calculator

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See how much free employer money you get from a 401(k) match and how much it grows over your career.

Roth vs Traditional IRA Calculator

Compare Roth and Traditional IRA after-tax value at retirement based on your tax rate today vs in retirement.

FAQ

Frequently Asked Questions

What annual return should I assume?+

For a diversified global stock portfolio, 6–7% nominal is a defensible long-run planning assumption. Use 4–5% for a balanced stock and bond mix, and always test a pessimistic case.

Does this account for inflation?+

No. The output is in nominal dollars. To see purchasing power, subtract expected inflation from your return input, or use the inflation-adjusted return calculator.

Is monthly compounding the right assumption?+

It is the standard convention for projections with monthly contributions and closely matches how a fund's value actually accumulates. Annual compounding produces a slightly lower figure.

How do fees change the result?+

Subtract the total expense ratio from your assumed return. A 1% fee on a 7% return removes roughly a quarter of the growth over 30 years — far more than most people expect.

Should contributions be at the start or end of the month?+

This model assumes end of month, the conservative convention. Contributing at the start adds roughly one extra month of growth per year.

Financial Disclaimer

This calculator is for educational and estimation purposes only. It does not provide financial, mortgage, tax, investment, or legal advice. Actual rates, payments, taxes, fees, insurance costs, eligibility, and loan terms vary by lender, location, credit profile, and market conditions. Always compare official offers and consult a qualified professional before making financial decisions.

Last updated June 2026 · Prepared by the mCalculator Editorial Team