Compound interest calculator
See how your money could grow with an initial amount, regular contributions, compound returns and time. This calculator also lets you compare a second scenario side by side so you can test different investing ideas.
Enter your numbers
Use the main scenario first, then add a comparison scenario if you want to test another option.
Quick scenarios
These are useful for testing article ideas and internal links.
Comparison scenario
Use this to compare another investing path against the main one.
Example ideas:
- $100/week vs $500/month
- $10,000 lump sum vs monthly investing
- Start now vs start 10 years later
Results
X-axis = years. Y-axis = estimated balance in dollars.
| Return rate | Estimated final value |
|---|
How to use this calculator
1. Add your starting amount
Enter the amount you already have invested or saved. If you are starting from zero, just leave it at 0.
2. Add contributions and return
Choose how often you plan to contribute and enter an estimated annual return to model long-term growth.
3. Compare another path
Use the comparison scenario to test questions like weekly vs monthly investing, or starting now vs later.
What compound interest means
Compound interest means your money can grow not only from your original amount and new contributions, but also from the returns already earned along the way. Over longer time frames, this can make a very large difference.
The calculator above is designed as an educational estimate. Real-world results can vary because of fees, taxes, inflation, market changes, contribution timing and actual investment performance.
Want the simpler explanation? Visit How compound interest works.
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