Calculadora de Interés Compuesto — Fórmula

## How Compound Interest Works

Compound interest is interest calculated on both the initial principal and the accumulated interest from previous periods.

### Formula

**FV = P(1+r)^n + PMT * [(1+r)^n - 1] / r**

Where:
- **FV** = Future value
- **P** = Initial investment (principal)
- **PMT** = Monthly contribution
- **r** = Monthly interest rate
- **n** = Total number of months

Ejemplo Resuelto

You invest $10,000 and add $200 per month at 7% annual return for 20 years.

  1. Monthly rate: 7% / 12 = 0.5833% (0.005833)
  2. Total months: 20 * 12 = 240
  3. Growth of initial investment: $10,000 * (1.005833)^240 = $40,387.39
  4. Growth of contributions: $200 * [(1.005833)^240 - 1] / 0.005833 = $104,185.06
  5. Future Value = $40,387.39 + $104,185.06 = $144,572.45
  6. Total contributions: $10,000 + ($200 * 240) = $58,000
  7. Total interest earned: $144,572.45 - $58,000 = $86,572.45