Investment Calculator

What is investment growth?

Investment growth is the change in your account balance as your starting money and contributions earn returns over time. This investment calculator estimates a future balance using your starting amount, monthly contribution, annual return, contribution increases, years invested and inflation.

The calculator compounds the balance monthly at the annual return divided by 12. It also estimates purchasing power by dividing the future value by cumulative inflation. That makes it easier to compare a projected balance with money you have today. People may also search for a stock market calculator, index fund calculator or mutual fund calculator. This tool estimates growth from your assumptions; it does not forecast a particular fund or investment.

Why investment growth matters

A future-value estimate can help you connect a savings habit with a goal, such as deciding whether your current plan supports the retirement you want. You can test how changing a monthly contribution or investing period affects the projection before you adjust a budget or workplace retirement contribution.

Inflation matters because a future dollar may buy less than a dollar today. The inflation-adjusted result gives you a more useful comparison for future spending, such as housing, health care and everyday costs. Treat both results as estimates, not promises: investment returns vary, and a steady assumed return does not capture every market upswing or decline.

Use the result as one input when you compare saving choices, not as a reason to take more investment risk. For retirement or investment decisions, confirm your assumptions and plan with a qualified financial professional.

How to use this investment calculator

1. Enter the amount you have already invested as the starting amount. Use the balance you expect to invest, rather than money set aside for bills or emergencies.
2. Enter the amount you plan to contribute each month. If you expect to raise contributions over time, enter the yearly increase. Use zero if you plan to keep the contribution unchanged.
3. Choose an annual return assumption and the number of years you expect to invest. The return is an input, not a forecast. Try more than one assumption to see how sensitive the estimate is.
4. Enter an inflation assumption to estimate the future value in today's dollars. Compare that result with the future balance when considering what your savings may buy.
5. Review the ending value, total contributions, growth and inflation-adjusted value together. Check that the inputs reflect what you can afford and the time period you have in mind.

Investment calculator example

How to read your investment calculator results

The ending value is the projected account balance at the end of the period. Total contributions show the money added under the schedule you entered; growth is the remaining increase in the projected balance after accounting for contributions and the starting amount.

In today's dollars is the estimate adjusted for cumulative inflation. It can help you think about future purchasing power, but it does not predict the cost of any particular expense. If the inflation-adjusted result feels low for your goal, consider whether you can save more, invest for longer or revise the goal. Each change comes with trade-offs, and actual returns may be higher or lower than the assumption.

How to improve your investment growth plan

1. 01

   Make contributions fit your budget

   Review recurring expenses and consider directing an affordable amount to your investment account each month. If you have a workplace retirement plan, you could consider raising your contribution gradually when your budget allows.

2. 02

   Increase contributions when your income rises

   When you receive a raise or finish paying a recurring bill, consider assigning part of that freed-up money to investing. Enter a yearly contribution increase in the calculator to see how a rising schedule changes the estimate.

3. 03

   Review costs and account choices

   Investment fees reduce the money that remains invested. Review the fees and investment options in your account materials, and consider asking a qualified financial professional how they fit your goals and risk tolerance.

4. 04

   Check the plan against your goal

   Compare the inflation-adjusted estimate with the amount you expect to need. If there is a gap, consider adjusting contributions, timing or the goal itself rather than relying on a higher return assumption.

Common investment calculator mistakes

• Treating the return as guaranteed

  The annual return is an assumption used in the calculation. Investment returns change over time, so test different assumptions and avoid treating one projected balance as certain.

• Ignoring inflation

  A large future balance can look more useful than it may feel in practice. Check the inflation-adjusted result when you are planning future spending.

• Entering contributions you cannot sustain

  A projection only reflects the schedule entered. Use a contribution that fits your budget, and update it if your income or expenses change.

• Assuming the estimate includes every cost

  The calculator uses the annual return you enter and does not show separate inputs for taxes or fees. Do not assume those costs are built into the result; review your account details when comparing investments.

The investment growth formula

Key terms

Annual return

The yearly rate of investment growth you enter as an assumption. Actual returns can differ.

Compounding

Growth earned on both the starting balance and the returns already added to the balance.

Inflation-adjusted value

A future amount expressed in today's dollars after accounting for cumulative inflation.