Plan with clearer numbers

Free Investment Calculator Online

See how a starting balance, monthly contributions, time and compound returns can work together. Compare assumptions, account for inflation and watch your projection redraw instantly.

Your plan is auto-saved only on this device

Build your plan

Start with what feels realistic. You can change it anytime.

Saved locally
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Fine-tune assumptions
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Your projection

After 20 years at an estimated 7% annual return

Live estimate
Projected balanceIn 20 years
$300,851

You contribute $130,000. Compound growth could add $170,851.

Total contributions$130,000
Estimated growth$170,851
Today's buying power$183,600

Your growth, year by year

Add a little moreAn extra $100 monthly could add $52,093.
Give it more timeFive more years could add $161,439.

This projection is for educational purposes only. It assumes a constant return, makes no allowance for taxes or fees, and does not guarantee future performance.

How this investment calculator works

The calculator grows your balance month by month using the annual return and compounding frequency you select. Your contribution is added at the end of each month, while the chart separates the money you put in from estimated market growth.

1

Start with your plan

Enter your current investment and the amount you expect to add each month.

2

Explore assumptions

Compare return rates and time horizons. Small changes can have a large long-term effect.

3

See the whole picture

Review your projected balance, contributions, estimated growth, and inflation-adjusted value.

Why time matters for compound growth

Compound growth means returns can earn returns of their own. In the early years, contributions often do most of the work. Over longer periods, the growth portion may become a larger part of the balance. That is why this calculator shows the full timeline instead of only a final number.

Contribute consistently

Regular deposits can reduce the pressure to find a perfect starting moment and keep your plan moving forward.

Compare, do not predict

Try several return assumptions. Real markets move unevenly, while a calculator uses a smooth average for clarity.

Remember purchasing power

Inflation can make a future amount buy less. The optional adjustment translates your result into today's money.

Investment calculator FAQ

How is investment growth calculated?

The calculator converts your annual return into an equivalent monthly growth rate based on the selected compounding frequency. It then applies growth and adds your contribution at the end of every month.

What annual return should I use?

Use a rate that matches the scenario you want to explore, then compare lower and higher assumptions. Returns vary and are never guaranteed; the preset rates are examples, not recommendations.

Does the calculator include inflation?

Yes. Open the fine-tune section and keep the inflation adjustment turned on to estimate the future balance in today's purchasing power.

Is my investment plan saved?

Yes. Your latest inputs are saved automatically in local storage on this device. Nothing is sent to an account or synced to a server.

Is this financial advice?

No. This is an educational planning tool. It does not include every fee, tax, market movement, or personal circumstance that may affect real results.

Continue planning with the Savings Calculator, Budget Tracker, Expense Tracker, or Percentage Calculator. Browse all free online tools.