MoneyBasisCompound Interest Calculator
What it estimates
This calculator estimates the future value of an investment using the starting amount, recurring contributions, expected annual return and investment period you enter. Future returns are assumptions, not guarantees.
How it calculates
FV = PV × (1 + r)^n + PMT × ((1 + r)^n − 1) / r
Future value uses monthly deposits and the monthly growth equivalent of the selected compounding frequency. PV is the starting balance, PMT is the monthly contribution, r is the monthly return, and n is the number of months. The annual return is a user-adjustable assumption, not a predicted market result.
Inputs
Starting balance · Monthly contribution · Expected return · Time horizon
Included / not modeled
Included
- Starting balance and end-of-month contributions
- Selected compounding frequency
- Optional inflation adjustment
Not modeled
- Taxes and investment fees
- Market volatility
Assumptions & limitations
- Returns are a user-adjustable assumption. The default is not a historical guarantee or a forecast.
- The input is a nominal annual return. For frequency k, monthly return is (1 + annual rate/k)^(k/12) − 1.
- Contributions are made at the end of each month.
- Taxes and fees are excluded. The optional inflation-adjusted value expresses purchasing power separately.