Investment Growth Calculator — Buy The Haystack
Buy The Haystack

What does your money actually become?

Compound interest is the most powerful force in investing. Move the sliders to see exactly what consistent investing actually turns into over time.

Starting amount $10,000
Monthly contribution $500/mo
Annual return 10.0%
Years investing 30 years
Final portfolio value
Total you invested
Market did for you
Portfolio growth over time
Year 5
Year 10
Year 20
Final year
Where your money comes from
What you put in
What the market added
The insight
Adjust the sliders to see your results.
How to capture this growth
The S&P 500 has returned approximately 10% annually over the last 30 years. A low-cost index fund like VOO charges just 0.03% to own it. Open a brokerage or robo-advisor account, set up automatic monthly contributions, and let compounding do the rest. The hardest part is starting — not managing it. Not financial advice — just the math.