Compound Interest Calculator
See how a recurring monthly deposit grows over 10, 20, or 30 years with compound interest.
About this calculator
Projects the future value of a savings or investment account by combining an opening balance with recurring monthly deposits and monthly compounding. Each month, interest is added to the balance at the annual rate divided by 12, then your contribution is added. Results are an estimate and do not account for taxes, fees, or inflation, and they assume a constant rate of return.
Field explanations
- Starting balance
- The amount you already have saved at the start.
- Monthly contribution
- The amount you add to the account every month.
- Annual interest rate
- The yearly rate of return on the balance. Divided by 12 to compute the monthly compounding rate.
- Time horizon
- How long you plan to keep saving, in years. Try 10, 20, and 30 to see how compounding accelerates over time.