Demystifying Mortgages: Understanding the Simple Mortgage Formula

Apr 29, 2024

When it comes to buying a home, one of the most important aspects to consider is the mortgage. Understanding how mortgages work can seem daunting, but it doesn't have to be. In this blog post, we will demystify mortgages and break down the simple mortgage formula.

What is a Mortgage?

A mortgage is a loan that is used to finance the purchase of a property. It allows individuals to buy a home without having to pay the full purchase price upfront. Instead, the borrower makes regular payments to the lender, which include both the principal amount borrowed and the interest charged.

The Simple Mortgage Formula

The simple mortgage formula helps to calculate the monthly mortgage payment. It takes into account three key factors: the loan amount, the interest rate, and the loan term. The formula is as follows:

Monthly Mortgage Payment = (Loan Amount * Interest Rate) / (1 - (1 + Interest Rate) ^ -Loan Term)

Let's break down each component of the formula:

Loan Amount:

The loan amount is the total amount borrowed from the lender. It is typically the purchase price of the property minus the down payment made by the borrower.

loan amount

Interest Rate:

The interest rate is the percentage charged by the lender for borrowing the money. It is an annual rate but is usually divided by 12 to calculate the monthly interest rate.

interest rate

Loan Term:

The loan term is the length of time over which the loan will be repaid. It is usually expressed in years.

loan term

By plugging these values into the simple mortgage formula, you can calculate the monthly mortgage payment. This calculation helps borrowers understand how much they need to budget for their mortgage each month.

Understanding the Components

Let's dive deeper into each component of the formula to gain a better understanding:


The principal is the initial amount borrowed and is the loan amount. It is the amount that needs to be repaid over time.



The interest is the cost of borrowing the money. It is calculated based on the principal amount and the interest rate. As the loan is paid off over time, the interest portion of the payment decreases, while the principal portion increases.


Loan Term:

The loan term determines the length of time over which the loan will be repaid. A longer loan term means lower monthly payments but more interest paid over the life of the loan. Conversely, a shorter loan term means higher monthly payments but less interest paid.

loan term explanation

Understanding the simple mortgage formula and its components can help potential homebuyers make informed decisions about their mortgage options. It allows them to calculate their monthly payments and assess the affordability of a property.

In Conclusion

Demystifying mortgages starts with understanding the simple mortgage formula. By knowing how the formula works and the factors it takes into account, individuals can better navigate the homebuying process. Remember, it's essential to consider your financial situation and consult with mortgage professionals to find the best mortgage option for your needs.