Interest on Interest
Your money earns interest, then that interest earns interest too. This creates exponential growth over time.
Compound Interest Calculator
Calculate how your investment grows over time with compound interest. See the power of compounding with detailed year-by-year breakdown and monthly contributions.
Calculator Inputs
Your Results
Enter your values and click Calculate to see results
Understanding Compound Interest
Time is Your Friend
The longer you invest, the more powerful compounding becomes. Start early to maximize growth.
Frequency Matters
More frequent compounding (daily vs. yearly) leads to slightly higher returns on your investment.
Compound Interest Formula
The formula calculation is standard for this mathematical operation.
A = P(1 + \frac{r}{n})^{nt} + PMT \times \frac{(1 + \frac{r}{12})^{12t} - 1}{\frac{r}{12}}Variables Explained:
Worked Examples
Basic Compound Interest
Initial investment of $10,000 at 7% compounded monthly for 10 years
Inputs:
- principal:
- 10000
- rate:
- 7
- time:
- 10
- compound:
- 12
- contribution:
- 0
Result:
$20,137.53 future value
Investment with Monthly Contributions
$5,000 initial + $200/month at 6% for 20 years
Inputs:
- principal:
- 5000
- rate:
- 6
- time:
- 20
- compound:
- 12
- contribution:
- 200
Result:
$112,198.45 future value
Retirement Savings
$25,000 starting amount + $500/month at 8% for 30 years
Inputs:
- principal:
- 25000
- rate:
- 8
- time:
- 30
- compound:
- 12
- contribution:
- 500
Result:
$1,006,266.38 future value