Use the Calculator
This is an estimate for educational purposes only. Actual results vary with fees, taxes, and changing rates.
Year-by-Year Growth
| Year | End Balance ($) | Contributed ($) | Interest Earned ($) |
|---|
Balances assume regular compounding and even monthly contributions.
How to Use This Tool
- Enter your initial amount, annual rate, and number of years.
- Choose a compounding frequency. Monthly is common for bank accounts.
- Optionally add a monthly contribution to see the impact of regular saving.
- Press Calculate to view the projected balance, total contributions, and interest.
Formula used: for principal \(P\), rate \(r\) (as a decimal), compounding periods \(n\) per year, time \(t\) in years, monthly contribution \(C\):
Without contributions: \(A = P(1+\frac{r}{n})^{nt}\).
With monthly contributions: \(A = P(1+\frac{r}{n})^{nt} + C \cdot \frac{(1+\frac{r}{n})^{nt} - (1+\frac{r}{n})^{nt - m_{start}}}{(1+\frac{r}{n})^{n/12}-1}\).
Worked Examples
Example 1: $5,000 at 6% for 10 years, monthly compounding, no contributions → about $8,983.
Example 2: $1,000 at 5% for 20 years with $100/mo → about $41,000+.
These examples show how time and steady contributions accelerate growth thanks to compounding.
Frequently Asked Questions
What is compound interest?
It’s interest on both your original money and the interest that’s been added before.
Which compounding option should I pick?
Monthly is typical for savings accounts and loans. Annual is fine for quick estimates. Daily yields only a tiny bit more than monthly at normal rates.
Is the result guaranteed?
No. This is an educational tool and ignores market volatility, fees, taxes, and rate changes.