**Introduction**

Calculating mortgage payments is a crucial step in the home-buying process, providing insight into the financial commitment involved. In this article, we’ll introduce a simple yet powerful 15 or 30 Year Mortgage Calculator using HTML and JavaScript. This calculator allows users to estimate their monthly mortgage payments based on the loan amount, interest rate, and loan term.

**How to Use**

- Input the loan amount in the designated field.
- Enter the annual interest rate for the mortgage.
- Choose the loan term – either 15 or 30 years.
- Click the “Calculate” button to obtain the monthly mortgage payment.

**Formula**

The formula used for calculating monthly mortgage payments is the standard loan payment formula:

$M=P×(+r)n−r(+r)n $

Where:

- $M$ is the monthly mortgage payment.
- $P$ is the loan amount.
- $r$ is the monthly interest rate (annual rate divided by 12).
- $n$ is the number of monthly payments (loan term multiplied by 12).

**Example**

Suppose you’re taking out a $200,000 mortgage with a 4% annual interest rate for 30 years. The monthly payment can be calculated using the formula mentioned earlier.

$r=120.04 $ $n=30×12$

After substituting these values into the formula, you can find the monthly payment.

**FAQs**

**Q: Can I use this calculator for other loan types?**

A: This calculator is specifically designed for 15 or 30-year mortgages. It may not provide accurate results for other loan types.

**Q: Is the monthly payment calculated the same for both 15 and 30-year terms?**

A: No, the loan term affects the monthly payment. A 30-year term generally results in lower monthly payments but higher overall interest payments.

**Q: How accurate is the calculator?**

A: The calculator provides a close estimate. However, actual payments may vary based on additional factors like property taxes and insurance.

**Conclusion**

This 15 or 30 Year Mortgage Calculator simplifies the process of estimating monthly mortgage payments, offering users a quick and efficient tool for financial planning during the home-buying journey.