How the calculation works
Each month, the calculator applies the return to the accumulated balance and then adds the monthly contribution. If the rate is annual, it is converted to an equivalent monthly rate.
Compound interest calculator
Simulate money growth over time with monthly contributions, interest rate, and a clear wealth chart.
Investment growth
Total invested
Final balance
Example
With $1,000 initially, $500 per month, 8% per year, and 20 years, the chart shows how interest becomes a larger share of the balance.
Frequently asked questions
Can the rate be monthly or annual?
Yes. Choose the rate type and the calculator converts it when needed.
When is the monthly contribution applied?
The monthly contribution is considered at the end of each month, after that month's return.
Does the result include taxes?
No. The calculation does not include taxes, fees, inflation, or investment costs.