Alex · $100/month for 40 years
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Total personal contributions: —
TWO VIDEO EXPERIMENTS · ONE FREE CALCULATOR
Investment Growth Simulator.
See what $100 a month could become, compare starting now against starting later, and test the contribution increases needed for a seven-figure portfolio.
Private by design. Calculations run entirely in this tab. Inputs are not saved or uploaded, and there is no account requirement.
NEW TO COMPOUNDING? START HERE
See how $100 a month can grow—then test the assumptions.
Begin with the compound-interest explanation to understand time, contributions and uncertain returns. The simulator below lets you reproduce the video’s example and change the variables.
Watch the compound-interest video ↗For the second experiment, watch How to Build a $1M Portfolio Starting With $100 per Month ↗.
No autoplay or embedded video player. YouTube opens only when you select a video link.
Change the assumptions
Enter your own hypothetical contribution, return, fees and timeline. All amounts are in USD.
Projected portfolio value—
Money contributed—
Investment growth—
Purchasing-power equivalent (today’s $)—
Target: $1,000,000—
How the balance grows
Portfolio Contributions
Year-by-year checkpoints
The table mirrors the chart, making the numbers readable without relying on the visualization.
| Year | Contributed | Growth | Portfolio value |
|---|
THE HIDDEN COST OF WAITING
What if you invest twice as much—but start ten years later?
This companion experiment uses the video's fixed assumptions: a 40-year comparison, a hypothetical 7% annual return compounded monthly, no fees, and end-of-month investing. It does not use the editable assumptions above.
Jordan · $200/month for the final 30 years
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Total personal contributions: —
These examples demonstrate the value of investment time, not a guarantee of market outcomes.
WATCH THE MATH EXPLAINED
Two videos. Two different questions.
The first explains compounding; the second explains the accounts, investments and contribution system behind a long-term goal.
How to Invest $100 a Month (The Power of Compound Interest)
What the $100 becomes, and why time matters more than the first few years suggest.
Watch the compounding explanation ↗
How to Build a $1M Portfolio Starting With $100 per Month
Long-term money, suitable account, diversification, automation and scaling contributions.
Watch the $1M system ↗The video examples use stylized, smooth growth—not actual market paths. Losses, volatility, changing contribution capacity, taxes and investor behavior affect real outcomes. The simulator does not select investments or assess suitability.
Building wealth also means defining what it must fund.
Use the Financial Freedom Number tool to explore spending-based goals rather than treating a million dollars as a universal target.