Investment Calculator
Project how an investment may grow with an initial balance, regular contributions and compound returns
Projected ending balance
How we calculated it
About the Investment Calculator
Investment growth depends on more than the starting balance. Contributions, time, return and compounding all interact, which is why small changes in assumptions can produce large differences over long periods.
This calculator is best used to compare scenarios rather than to predict a guaranteed outcome. Market returns vary, and taxes, fees and inflation can materially change the amount that ultimately benefits you.
How to Use the Investment Calculator
- Enter the starting investment balance.
- Enter the amount and frequency of any recurring contributions.
- Enter the expected annual return and time horizon.
- Calculate the projected value, then test lower-return and higher-contribution scenarios before relying on one outcome.
How the Calculation Works
The existing principal is compounded over the selected time horizon, while recurring contributions are added and allowed to grow according to their timing.
Future value is the combination of the compounded starting balance and the future value of contributions. Total gain is future value minus the money you actually contributed.
Worked example
Investment Calculator Worked Example
$10,000 start plus $300 monthly
With no investment return, five years of $300 monthly contributions add $18,000 to the $10,000 starting balance, giving $28,000. A positive return would increase the projected value above that amount because both the original money and earlier contributions have time to grow.
Result guide
Understanding Your Investment Calculator Result
The projection is highly sensitive to return and time. If the plan only reaches its target under an aggressive return assumption, it may be safer to increase contributions or extend the horizon.
Before you rely on the answer
Assumptions and Limitations
- Return is modeled as a steady rate even though real investments fluctuate.
- Contribution timing follows the selected schedule.
- Taxes, fees and inflation are excluded unless explicitly entered.
Practical tip
Using This Result in Practice
Track contributions and investment performance separately. Increasing the saving rate is a controllable lever, while market return is not.
Related calculations
Useful Calculations to Continue With
If you want a cleaner time-value-of-money projection from a defined rate and cash flow, use the Future Value Calculator.
If the investment has already ended and you only need the gain relative to cost, use the ROI Calculator.
Common questions
Investment Calculator FAQ
Can this calculator predict stock-market returns?
No. It models the return rate you enter as a scenario; actual market returns vary from year to year.
Do regular contributions make a big difference?
They can. Over long periods, recurring contributions add principal and give earlier deposits more time to compound.
Should I include investment fees?
Yes when they are material. Fees reduce the return you actually keep, so a net-return assumption is often more realistic than a gross market return.