Finance tools
Investment calculator
Use this free investment calculator to estimate how a starting balance and recurring deposits could grow over time at an assumed return rate. It works as a monthly investment calculator or broader investment growth calculator: see your projected ending balance, total contributions, and interest earned—or switch modes to solve for monthly contribution, return rate, starting amount, or years to a goal. Includes a chart, year-by-year table, and CSV/PDF export with no sign-up. Related: compound interest calculator, 401(k) calculator, and FIRE calculator. Illustrative estimates only—not investment or tax advice.
What is an investment calculator?
An investment calculator is a planning tool that estimates future account value when you invest a lump sum, add money on a schedule, or both—using one assumed annual return rate and compound growth.
Typical questions: “How much will I have in 10 years?” and “How much should I invest each month to reach $250,000?” People use it for taxable brokerage accounts, extra retirement savings, education funds, or any quick what-if before deeper planning with a professional.
Real portfolios move with markets, fees, and taxes. Treat results as education and rough planning—not a forecast of what you will actually earn.
How to use this investment calculator
Use the mode selector above the inputs to project an ending balance or solve for one missing variable—contribution, return, starting amount, or years. Preset chips load popular examples ($100/mo for 20 years, retirement savings, and the default $20k + $1k/mo scenario).
Pick what to solve
Project balance (default), Contribution, Return rate, Starting amount, or Years to goal—each mode keeps the same inputs but solves a different output.
Enter amounts and horizon
Starting balance, recurring contribution, contribution frequency (weekly through annual), years, and annual return %. In solve modes, set target balance to your dollar goal.
Set compounding
Match compounding frequency to your model, choose beginning vs end contribution timing, and optionally add inflation % in Advanced for a real-dollar readout.
Read results and export
Check ending balance, total contributions vs interest, the line chart, and the paginated year-by-year table. Export summary plus yearly schedule CSV when you need a spreadsheet.
Five solve modes at a glance
- Project balance — ending value from today’s plan
- Contribution — payment needed to hit a target
- Return rate — assumed % needed to hit a target
- Starting amount — lump sum needed today
- Years to goal — time to reach a target
Inputs explained
Every mode shares the same core fields—the mode selector only changes which output is solved:
- Starting amount — lump sum invested today
- Recurring contribution — each payment at weekly, biweekly, monthly, quarterly, semiannual, or annual frequency
- Years to grow — full planning horizon (fractional years supported in solve output)
- Annual return rate — fixed nominal assumption before optional inflation adjustment
- Target balance — goal dollar amount when solving contribution, rate, starting amount, or years
- Contribution timing — beginning vs end of period (matches many payroll-deposit models)
Open Advanced for optional inflation % to show an inflation-adjusted ending balance next to nominal results, or pair with the inflation calculator for separate CPI what-ifs.
Realistic return assumptions
Choose a return rate you can explain to yourself or an advisor—not the best year the market ever had. U.S. planning discussions often cite long-run stock-heavy averages around 6–7% before inflation, but your asset mix, fees, and time horizon may differ.
| Planning band | Typical use |
|---|---|
| ~5% | Conservative / bond-heavy mix |
| ~6–7% | Balanced long-run illustration |
| 8%+ | Stress-test only—not a guarantee |
Tip: run a low and high rate
Change only the return % and compare ending balances—no need to guess one perfect number.
Investment calculator vs compound interest
Both tools show how money can grow with compounding. This investment calculator is built for savings goals: lump sum plus recurring contributions, with five solve modes (including “how much per month?” and “what return do I need?”).
Our compound interest calculator leads with compound-interest language and Growth / Compare / Goal workflows—better when that is the exact phrase you searched for.
Need textbook time-value-of-money labels (PV, PMT, N, I/Y)? Try the future value calculator or time value of money calculator—same math family, different layout.
Compounding frequency
Compounding frequency controls how often earned returns are reinvested within the model. It is independent of how often you contribute—you might transfer weekly while the account compounds monthly.
| Compounding setting | When it helps |
|---|---|
| Daily | Equity illustrations; slightly higher ending balance at the same nominal rate |
| Monthly | Common default; aligns with many brokerage growth models |
| Quarterly / annual | Simpler long-range sketches; lower ending balance vs daily at same rate |
At a fixed annual return %, more frequent compounding increases ending balance modestly. Run two scenarios if you are deciding between daily and monthly assumptions.
Monthly investing examples
These scenarios use $0 or fixed starting balances, monthly contributions, and monthly compounding unless noted. Tap a preset chip above the calculator to load a close match.
| Scenario | Approx. contributed | Approx. ending balance |
|---|---|---|
| $100/mo · 20y · 7% | ~$24,000 | ~$52,000 |
| $200/mo · 20y · 7% | ~$48,000 | ~$104,000 |
| $10k lump · 10y · 6% | $10,000 | ~$18,194 |
| $1,000/mo · 10y · 6% + $20k start | ~$140,000 | ~$200,267 |
Growth is not guaranteed
Figures assume a constant return every year. Real markets rise and fall—treat these rows as illustrations, then enter your own assumptions in the calculator above.
Forward projection vs rate of return
Forward planning and backward performance are different questions. Pick the tool that matches yours:
| Question | Use this page | Use rate of return tool |
|---|---|---|
| How much could I have in 10 years? | Yes — assume a fixed return | No |
| What return did I actually earn? | No | Yes — enter start, end, and flows |
| What monthly deposit hits $500k? | Yes — Contribution mode | No |
Open the rate of return calculator for backward-looking performance. For uneven project cash flows, use the NPV calculator.
Investment calculator formula
With lump sum PV, level payment PMT, per-period rate i, and n periods, future value is:
FV = PV × (1 + i)n + PMT × [((1 + i)n − 1) / i] for end-of-period payments (beginning timing adds one extra growth factor on each deposit).
Mini example (conceptual)
$10,000 today at 6% compounded monthly for 10 years with no further deposits → about $18,194 in this tool—mostly from compounding on the initial lump sum.
You enter an annual return %; the engine converts it to i based on compounding frequency and counts n from years plus contribution schedule.
Retirement, FIRE, and employer plans
Retirement and employer-plan calculators handle account rules and tax treatment. This page answers a simpler question: “If I save this much at this assumed return, what balance might I reach?”
- FIRE calculator — financial independence number, savings rate, years to FIRE
- 401(k) calculator — payroll deferrals, employer match, plan limits
- Roth IRA calculator — contribution limits and tax-free growth illustration
- Net worth calculator — assets minus liabilities today, not forward growth
You can add results from those tools for a rough total-portfolio picture. This version does not model withdrawals, required minimum distributions, or Social Security.
Taxes and fees
All results are pretax and ignore account type (taxable brokerage vs IRA vs 401(k)). Capital gains rates, dividend taxation, and state taxes can materially change spendable outcomes.
Advisory fees, expense ratios, and commissions are not subtracted automatically. Many planners lower the return % by 0.25–1.0 points as a rough fee placeholder, or use the mutual fund calculator for load and ER scenarios on fund contributions.
Optional inflation % in Advanced adjusts ending balance for purchasing power—it is not a tax model. For CPI-only questions, see the inflation calculator.
Worked example
Default preset — $20,000 start, $1,000/month, 10 years, 6% return, monthly compounding, end-of-period contributions → about $200,267 ending balance ($140,000 contributed including the start; ~$60,267 growth).
Contribution solve — With the same start, rate, and horizon, targeting ~$200,267 solves to about $1,000/month (use Contribution mode to verify).
Try it live
Load the $20k + $1k/mo · 10y · 6% preset chip, then switch modes without clearing inputs to explore other solves.
Limitations
This investment growth calculator stays deliberately simple. It does not include:
- Market volatility, bear markets, or sequence-of-returns risk
- Monte Carlo simulations or historical index back-tests
- Withdrawals, decumulation, or “how long will my money last?”
- Tax brackets, wash sales, or account-specific rules
- Irregular or one-off cash flows (try the NPV calculator or mutual-fund IRR tools)
See related tools below for specialized scenarios. None of this replaces personalized advice or a full financial plan.
More free tools
Discover more calculators for time tracking, payroll, and HR.
Frequently asked questions about this investment calculator
How much will $10,000 invested be worth in 20 years?
With no extra deposits, $10,000 at a 6% annual return for 20 years (monthly compounding) grows to about $33,100 in this calculator.
Change the return rate, add monthly contributions, or enter your own numbers above for a personalized estimate.
If I invest $100 a month for 20 years, how much will I have?
With a $0 starting balance, $100/month for 20 years at 7% (monthly compounding), you would have about $52,000—roughly $24,000 contributed and the rest from growth. Tap the $100/mo · 20y preset to try it in this monthly investment calculator.
How much do I need to invest to make $10,000 a month?
No monthly deposit guarantees $10,000 a month in retirement income—withdrawals, taxes, and market risk all matter. Many planners use the 4% rule as a rough guide: annual spending × 25. At $10,000 per month ($120,000 per year), that suggests about a $3 million portfolio before taxes—not a promise.
Model FI targets in our FIRE calculator. This tool projects saving and growth, not retirement paychecks.
How much do I need to invest to make $3,000 a month?
Using the same 4% rule illustration as a planning shortcut: $3,000 per month is $36,000 per year. Multiply by 25 (or divide by 0.04) for a rough portfolio target of about $900,000 before taxes—again, not a guarantee.
Adjust for your spending, tax situation, and withdrawal strategy in the FIRE calculator. Use this investment calculator to model how you might build toward a balance over time.
Is it better to invest a lump sum or invest monthly?
Both are valid. A lump sum puts more money to work immediately when markets rise; monthly investing (dollar-cost averaging) spreads purchases over time and can feel easier to stick with.
This calculator models either approach: enter a starting amount, recurring contributions, or both, then compare scenarios. It does not predict which strategy will earn more in real markets.
What rate of return should I use in an investment calculator?
Many people use 5–7% for a diversified, stock-heavy long-run illustration, or 3–4% for bonds or high-yield savings—then discuss inflation separately.
Past averages are not guarantees. Run the same plan at two or three rates to see a range instead of betting on one number.
What is the investment calculator formula?
Future value with a lump sum plus level payments: FV = PV × (1 + i)n + PMT × annuity factor, where i is the rate per compounding period and n is the number of periods.
Enter an annual return % and compounding frequency here—the tool converts to i and n for you. The results panel summarizes the same math in plain language.
How do I calculate investment growth with regular contributions?
Enter your starting amount, recurring contribution, contribution frequency, years, and annual return %, and keep Project balance mode selected.
The chart and yearly table split total contributions from interest earned. Export CSV for the full schedule.
Can I solve for how much to invest each month?
Yes. Select Contribution mode, enter your target balance, starting amount, return rate, and years—the calculator solves the recurring payment needed (weekly through annual frequency).
What's the difference between an investment calculator and a compound interest calculator?
Both project compound growth. An investment calculator like this one is built around savings plans—starting balance plus recurring deposits—and five solve modes (contribution, return, starting amount, or years to a goal).
Our compound interest calculator centers on compound-interest wording with Growth, Compare, and Goal workflows.
What's the difference between an investment calculator and a rate of return calculator?
This investment calculator is forward-looking: you assume a return and see a future balance. The rate of return calculator is backward-looking: you enter starting value, ending value, and cash flows to estimate the return you already earned.
Does this investment calculator include taxes or fees?
No. Results are pretax and do not subtract advisory fees, fund expense ratios, or brokerage costs unless you lower the return rate yourself to approximate them.
For fund loads and expense ratios on contributions, try the mutual fund calculator.
Do weekly or monthly contributions change the result?
Yes, slightly. More frequent contributions can raise the ending balance because money is invested sooner. Pick weekly, biweekly, monthly, or another schedule in Contribution frequency to match how you actually save.
Does compounding frequency change the result?
Yes. At the same nominal annual return, daily compounding produces a slightly higher ending balance than annual compounding. Match the setting to your model, or use monthly as a common default.
What is total interest vs total contributions?
Total contributions are everything you put in—the starting amount plus every recurring payment. Total interest earned (growth in this model) is ending balance minus those contributions.
Both show in the results breakdown and in CSV/PDF export.
Can this model stocks or the S&P 500?
You can enter any fixed annual return % as an illustration, including rates inspired by long-run equity averages. We do not back-test the S&P 500, replay historical index paths, or forecast future market returns.
Is this a stock investment calculator?
It is a fixed-rate investment growth calculator, not a stock picker or index simulator. You can illustrate a stock-heavy portfolio with an assumed return, but we do not model tickers, dividend timing, or historical index charts.
For cost basis on shares, use the stock average calculator; for realized performance, use the rate of return calculator.
What starting amount do I need to reach $1 million?
It depends on how much you contribute each period, your assumed return, and how long you invest. Use Starting amount mode, set a $1,000,000 target, and enter your contribution, rate, and years—the tool solves the lump sum needed today.
How does this relate to a 401(k) or IRA?
Employer plans add match rules and IRS limits. Model payroll deferrals and match in our 401(k) calculator or Roth IRA calculator, then use this tool for taxable brokerage savings or rough total-portfolio what-ifs at a fixed return.
Is this financial advice?
No. This investment calculator is for education and rough planning only. Read Investor.gov — Introduction to investing for basics, and talk with qualified professionals for advice tailored to you.