Fixed vs Adjustable Rate Mortgages: Which Is Right for You?

One of the most consequential decisions you will make when financing a home is choosing between a fixed-rate mortgage (FRM) and an adjustable-rate mortgage (ARM). Each has genuine advantages and disadvantages, and the right choice depends on factors specific to your situation — including how long you plan to stay in the home, your risk tolerance, and the current interest rate environment.

How Fixed-Rate Mortgages Work

With a fixed-rate mortgage, your interest rate is locked in for the life of the loan. On a 30-year fixed mortgage, you will make the same principal and interest payment every month for 360 months. This predictability is the product's primary appeal: you know exactly what you owe, and rising market rates cannot touch you. The 15-year fixed option typically carries a rate 0.5% to 0.75% lower than a 30-year but requires a higher monthly payment because you pay off the principal in half the time.

How Adjustable-Rate Mortgages Work

An ARM starts with a fixed period, then adjusts periodically based on a market index plus a margin set by the lender. The most common ARMs are the 5/1, 7/1, and 10/1 varieties. A 5/1 ARM has a fixed rate for the first five years, then adjusts once per year. ARMs come with caps that limit how much the rate can change at the first adjustment, each subsequent adjustment, and over the loan's lifetime. A common cap structure is 2/2/5.

When a Fixed-Rate Makes More Sense

A fixed-rate mortgage is typically the better choice if you plan to stay in the home for more than 7 to 10 years, when rates are near historic lows, or when you need the predictability that comes from a consistent payment. Fixed rates are also simpler to understand and plan around.

When an Adjustable-Rate Makes More Sense

ARMs offer lower initial interest rates — often 0.5% to 1.5% below comparable fixed rates — resulting in lower monthly payments during the fixed period. If you are confident you will sell or refinance before the first adjustment, you capture those savings without taking on rate risk. ARMs can also make sense when a 1% rate difference on a large loan amount represents thousands of dollars per year in savings.

The Break-Even Analysis

Calculate the break-even point: take the monthly payment savings of the ARM during the fixed period and compare it to the maximum additional interest you might pay if rates rise to the ARM's cap after adjustment. If you will sell or refinance well before the break-even point, the ARM may be advantageous. If you might stay longer, the fixed rate's certainty is more valuable.

Review our complete mortgage resource library to learn more, or speak with a loan specialist to model out both options with current rates.