Compound interest calculator.
Explore investment growth with recurring contributions and flexible compounding.
UNDERSTAND THE ESTIMATE
How to use this calculator
Enter a starting investment, a recurring monthly contribution, an annual rate and a duration. Choose compounding frequency and whether deposits arrive at the start or end of each month.
The calculation
For the initial investment, A = P × (1 + r/n)^(nt), where r is the nominal annual rate as a decimal, n is compounding periods per year and t is years. Monthly deposits grow at the equivalent monthly rate. Continuous compounding uses A = P × exp(rt). At zero interest, the final balance is the initial investment plus all deposits.
Uses constant rates and regular monthly cash flows. Taxes, fees, inflation and changing rates are excluded. Estimates are not financial advice.
SEC Investor.gov compound interest calculator ↗ILLUSTRATIVE EXAMPLE
Follow the numbers
Start with 1,000, add no deposits, and assume 10% interest compounded annually for one year. The final balance is 1,100, including 100 of interest. This is a constant-rate illustration, not a return forecast.
Does choosing a currency convert my investment?
No. It changes the money labels. Taxes, fees, inflation and changing returns are excluded, and real account crediting schedules can differ from the model.