**Introduction:** Welcome to our 25-Year Annuity Calculator, a valuable tool for individuals planning long-term investments with a fixed annual interest rate. An annuity provides a series of regular payments over a specified period, and this calculator helps you estimate the future value of your investment over 25 years.

**Formula:** The formula used in this calculator is derived from the present value of an annuity formula: ��=�×(1−(1+�)−�)�*P**V*=*r**P*×(1−(1+*r*)−*n*), where ��*P**V* is the present value, �*P* is the initial investment, �*r* is the annual interest rate (as a decimal), and �*n* is the number of years.

**How to Use:**

- Enter your initial investment in the designated field.
- Input the annual interest rate as a percentage.
- Specify the number of years for the annuity.
- Click the “Calculate” button to obtain the estimated future value.

**Example:** Suppose you invest $50,000 with an annual interest rate of 4%. The calculator will estimate the future value of your investment after 25 years based on the provided information.

**FAQs:**

*Q: Can I use this calculator for monthly investments?*A: No, this calculator is designed for a one-time initial investment.*Q: Does the calculator account for inflation?*A: No, the calculator assumes a fixed annual interest rate without considering inflation.*Q: What happens if I enter a negative value for the initial investment?*A: The calculator will prompt you to enter a valid positive value.*Q: Can I use this calculator for different time periods, like 10 or 15 years?*A: Yes, you can adjust the number of years to suit your desired investment duration.

**Conclusion:** Our 25-Year Annuity Calculator empowers you to make informed decisions about your long-term investments. Use it to estimate the future value of your initial investment and plan for a secure financial future.