Compound Interest Calculator
Investment Growth Calculator
Project how an investment could grow from an initial amount, monthly investments, an assumed annual return, and time.
Use the Investment Growth Calculator
Your results
- Estimated ending balance
- $0.00
- Total contributions
- $0.00
- Estimated interest or growth
- $0.00
Year-by-Year Projection
How this calculator works
- What it does
- Project how an investment could grow from an initial amount, monthly investments, an assumed annual return, and time.
- Inputs used
- The estimate uses initial investment, monthly investment, annual interest or return rate (%), and number of years.
- Calculation approach
- The calculator applies the relationships defined for the investment growth calculator to those inputs and updates estimated ending balance, total contributions, and estimated interest or growth.
- How to read the result
- Treat the result as a scenario based on the values entered. Compare a few reasonable inputs and consider costs, taxes, timing, or risks that the calculator does not include.
How to Use This Calculator
- Enter Initial investment and Monthly investment using values that match the scenario you want to evaluate.
- Enter Annual interest or return rate (%) and Number of years using values that match the scenario you want to evaluate.
- Review the assumptions for the investment growth calculator, especially rates, time periods, and optional amounts.
- Select Calculate to update the results, then adjust one input at a time to compare scenarios.
Understanding the Results
- Estimated ending balance
- The estimated value at the end of the selected period after applying the entered contributions, rates, and timing assumptions.
- Total contributions
- The amount added from contributions, separate from investment growth or interest.
- Estimated interest or growth
- The estimated interest or growth estimated by the Investment Growth Calculator using initial investment, monthly investment, and annual interest or return rate (%) and the other values entered.
Common Mistakes
- Treating an assumed return, growth rate, inflation rate, or yield as guaranteed.
- Leaving out taxes, fees, inflation, or timing differences that can affect real-world results.
- Mixing monthly and annual figures or entering percentages in the wrong units.
- Relying on one projection instead of comparing a range of reasonable assumptions.
Frequently asked questions
What does this investment growth calculator estimate?
It projects an ending balance from the starting amount, monthly additions, annual rate, time period, and the compounding frequency fixed for this calculator.
When does the Investment Growth Calculator assume contributions are added?
Monthly contributions are converted into an equivalent amount for each compounding period and are treated as end-of-period additions.
Is the annual rate used by the Investment Growth Calculator guaranteed?
No. It is a constant scenario assumption. Investment returns and variable savings rates can change, and actual results may be higher or lower.
Does the Investment Growth Calculator include taxes, inflation, or fees?
No. The projection is nominal and excludes taxes, inflation, account fees, transaction costs, and withdrawals.
How does compounding frequency affect the Investment Growth Calculator?
More frequent compounding adds interest to the balance sooner, allowing that interest to participate in later growth when the nominal annual rate is positive.
What does the Investment Growth Calculator calculate?
Project how an investment could grow from an initial amount, monthly investments, an assumed annual return, and time. The result is based only on the inputs and assumptions shown on the page.
How should I interpret the estimated ending balance from the Investment Growth Calculator?
Use it as an estimate for the scenario entered, not as a guarantee or personal recommendation. Test changes to initial investment, monthly investment, and annual interest or return rate (%) to see which assumptions have the greatest effect.