Investment Calculator
Project future value based on contributions, rate of return and time horizon.
Inputs
$
$
%
yrs
Result
Future Value$300,850.72
Total Contributions$130,000.00
Interest Earned$170,850.72
About the Investment Calculator
The Investment Calculator projects the future value of a lump-sum investment plus recurring monthly contributions at a given annual return, so you can plan long-term goals.
Calculation method
Combines the future value of a lump sum and the future value of an annuity of contributions, compounded monthly.
FV = P(1+r)^n + PMT × ((1+r)^n − 1)/r
r = APR/12, n = years × 12How to use this calculator
- Enter the starting amount you already have invested.
- Enter your monthly contribution.
- Enter an expected annual return and time horizon in years.
Example
$10,000 starting, $500/month for 20 years at 7% grows to about $299,000, of which $130,000 came from contributions and $169,000 from compounding.
Frequently asked questions
What annual return should I assume?
The US stock market has averaged about 10% before inflation and 7% after inflation since 1928. Use 6–7% for a conservative long-term plan.
Are returns guaranteed?
No. Actual returns vary widely year to year. The tool projects a smooth average; real portfolios have losing years too.
Does this account for taxes or fees?
No. Subtract about 0.5–1% from the assumed return to approximate typical fund fees, and factor in capital gains tax on withdrawals from taxable accounts.
Disclaimer: This calculator is for informational and educational purposes only and does not constitute financial, tax, or legal advice. Consult a qualified professional for decisions specific to your situation.