Free tool
Compound Interest Calculator
Estimate how money can grow over time with compound interest. The calculator separates total contributions, interest earned and final balance.
Updated July 2026
Final balance
$6,479.38
Total invested
$5,800.00
Interest earned
$679.38
Monthly rate used
0.8%
Educational estimate only. This is not investment, tax or credit advice.
How to use
- Fill in the fields for your use case.
- Review the result generated by the tool.
- Adjust values to compare scenarios or produce a cleaner output.
Example
With $1,000 initially, $200 added every month for 24 months at 0.8% monthly interest, the result shows how much came from contributions and how much came from growth.
What is included
- Initial amount.
- Monthly contribution.
- Monthly or annual rate converted automatically.
- Term in months.
Method and limitations
Contributions and rate
The simulation combines the initial amount, monthly contributions, and compound growth over the selected term. Annual rates are converted to an equivalent monthly rate.
Gross educational estimate
Taxes, inflation, management fees, penalties, and investment risk are not included. Use the result to compare scenarios, not as financial advice.
Frequently asked questions
Should I enter a monthly or annual rate?
You can choose either. If you enter an annual rate, the tool converts it to an equivalent monthly rate.
Does it include taxes or inflation?
No. The result is a gross estimate for comparing simple scenarios.
Can I use it for debt?
Yes, as a generic simulation. Real credit products can include fees, penalties and different compounding rules.