See how compound interest grows your savings
Enter an initial deposit, a monthly contribution, an annual rate, and a number of years to project the final amount, total contributions, and total interest earned. A bar chart and year-by-year table make the compounding effect visible.
What the calculator shows
Final amount
The projected balance after the chosen number of years, compounded monthly.
Contributions vs. interest
Total money you put in versus interest earned — the gap is the power of compounding.
Growth chart
A simple bar chart, one bar per year, showing how the balance curve steepens over time.
Yearly table
Per-year deposits, interest earned, and balance so you can trace every step.
1. Set up your scenario
- Enter the initial deposit (use zero to start from nothing).
- Enter the monthly contribution you can sustain.
- Pick an annual interest rate and a time horizon between 1 and 60 years.
- Press Calculate to see the projection, chart, and yearly table.
2. Compare scenarios
| What to change | What it teaches you |
|---|---|
| Raise the monthly contribution | How steady saving beats chasing a higher rate |
| Extend the years | Why starting early matters more than starting big |
| Lower the rate | What a conservative assumption looks like |
Important: estimates only, not financial advice
This calculator and guide are for estimation and education only. They are not financial advice. The projection assumes a constant rate and monthly compounding; real returns fluctuate and investments can lose value. Your inputs are processed entirely in your browser and never sent to a server.
Sources
FAQ
How is the final amount calculated?
The tool compounds monthly: each month the balance grows by the monthly rate and then your monthly contribution is added. The yearly table shows deposits, interest earned, and balance per year.
What does the bar chart show?
One bar per year, scaled to the final balance, so you can see visually how growth accelerates as interest starts earning its own interest.
Can I model a lump sum with no monthly contributions?
Yes. Set the monthly contribution to zero and the tool projects growth of the initial deposit alone.
Is the interest rate guaranteed?
No. The rate you enter is an assumption for the projection. Real investment returns vary and can be negative.
Is this financial advice?
No. The calculator produces estimates from the numbers you enter. It is not financial advice; consider speaking with a qualified professional for investment decisions.