Want more scenarios like this? Explore the weekly hub and monthly hub, then run your own numbers in the calculator.
Investing $200 a month in the S&P 500 for 20 years can compound meaningfully over time — here’s the simplest way to think about it:
Here’s how $200/month can compound over 20 years under different return assumptions. Then use the calculator to run your own S&P 500-style index fund scenarios.
Open Money Growth calculatorThe S&P 500 is a stock index (not a guaranteed return). The best way to plan is to model a few different annual return assumptions. Below is an example of $200 per month invested for 20 years under three scenarios.
| Assumed annual return | Years | Monthly contribution | Approx. balance (estimate) |
|---|---|---|---|
| 5% (conservative) | 20 | $200 | |
| 7% (middle) | 20 | $200 | |
| 10% (optimistic) | 20 | $200 |
These are rough estimates to show how sensitive outcomes are to the return assumption. Use the calculator below to run your own numbers and timelines.
Open the Money Growth calculator and test your own timeline, contribution amount, and return assumptions. Try 5%, 7%, and 10% to see a range.
Keep exploring — these pages connect directly to calculators so you can run your own numbers.
No. Markets vary year to year. The best practice is to model multiple scenarios and plan conservatively.
Start where you can be consistent. If you can increase contributions over time, your future balance can grow significantly.
Yes. Time is a powerful lever in compounding.
Use the Money Growth calculator and adjust contributions, years, and rate.
These pages connect to calculators so you can run your own numbers.