A 5/1 ARM (Adjustable Rate Mortgage) offers a fixed interest rate for the first 5 years, then adjusts annually based on a market index (typically SOFR). The initial rate is usually 0.5–1% lower than a 30-year fixed, which means meaningful savings in the short term. The risk: if rates rise during the adjustable period, so does your payment. This calculator shows your initial payment and models potential rate scenarios.
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After the initial 5-year fixed period, the rate adjusts every year based on a benchmark index (usually SOFR) plus a lender margin (typically 2.75%). Most 5/1 ARMs have a 2/2/5 cap structure: rates can go up no more than 2% at the first adjustment, 2% at each subsequent adjustment, and 5% total over the life of the loan.
Is a 5/1 ARM risky?
It depends on your timeline. If you're confident you'll sell or refinance within 5 years, the ARM saves you money with near certainty. If you end up staying longer and rates rise, your payment could increase significantly. The 2/2/5 cap structure limits how high it can go, but planning for the worst-case payment is wise.
Who should consider a 5/1 ARM?
ARMs make the most sense for buyers who plan to move within 5–7 years, expect their income to rise substantially, or are buying in a period of unusually high rates and expect to refinance when rates fall. They're popular with physicians, military families, and corporate relocators who know they'll move.
How much lower is an ARM rate than a 30-year fixed?
Typically 0.5–1% lower, though this spread varies with market conditions. In periods of an inverted yield curve (like 2023–2024), the spread can narrow significantly and the ARM savings diminish, making fixed rates more attractive on a relative basis.
Can I refinance out of an ARM into a fixed rate?
Yes — refinancing from an ARM to a fixed-rate loan is very common. Many borrowers take an ARM intentionally and then refinance before the fixed period ends. The risk is that rates could be higher when you go to refinance, locking you into a higher fixed rate than if you'd chosen fixed from the start.