Investment Growth Calculator
See exactly how your portfolio grows with the power of compound interest. Adjust any variable below.
Investment Growth Calculator
See how your investments grow over time with compound interest.
Total Value
$252,111
Total Contributed
$73,000
Interest Earned
$179,111
Growth Over Time
How to Use This Calculator
Enter your starting investment amount, how much you'll contribute monthly, your expected annual return rate, and how many years you plan to invest. The calculator shows your total portfolio value, total contributions, and interest earned at each milestone.
What Is a Realistic Return Rate?
The S&P 500 has historically returned about 10% annually before inflation, or roughly 7% after inflation. A diversified index fund portfolio might reasonably expect 6–8% real returns over the long term, though past performance doesn't guarantee future results.
The Power of Starting Early
Time is your greatest asset. Someone who invests $200/month for 30 years at 7% ends up with far more than someone who invests the same amount for 20 years — not because they contributed more, but because of the compounding on top of compounding in those extra 10 years.