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

Fixed-rate mortgages keep the same interest rate for 30 years. Adjustable-rate mortgages (ARMs) start lower but can change. The right choice depends on how long you'll stay in the home and your tolerance for payment uncertainty.

How Each Loan Type Works

Fixed-Rate Mortgage

Your rate and payment stay the same from month 1 to month 360. If you lock 6.5% today, you pay 6.5% in 2040, regardless of what happens to market rates.

Adjustable-Rate Mortgage (ARM)

ARMs have two phases:

1. Fixed period: Rate stays constant (typically 5, 7, or 10 years)
2. Adjustment period: Rate changes annually based on a market index

A "5/1 ARM" means 5 years fixed, then adjustments every 1 year. A "7/6 ARM" means 7 years fixed, then adjustments every 6 months.

Real Payment Comparison

Let's compare a $400,000 loan with these January 2026 rates:

• 30-year fixed: 6.75%
• 5/1 ARM: 5.875% (initial rate)

Monthly Payments (Principal & Interest)

Monthly savings with ARM (years 1-5): $228

Total savings over 5 years: $13,680

But here's the catch: after year 5, the ARM rate adjusts. If rates rise to 8%, your payment jumps to $2,889—$295 more than the fixed option.

ARM Rate Caps Explained

ARMs include caps that limit how much your rate can change:

• Initial cap: Maximum increase at first adjustment (typically 2%)
• Periodic cap: Maximum increase per adjustment after that (typically 2%)
• Lifetime cap: Maximum increase ever (typically 5% above initial rate)

For a 5/1 ARM starting at 5.875% with 2/2/5 caps:

• After year 5: Maximum rate is 7.875% (5.875% + 2%)
• After year 6: Maximum rate is 9.875% (7.875% + 2%)
• Lifetime maximum: 10.875% (5.875% + 5%)

At the 10.875% lifetime cap, your $400,000 loan payment becomes $3,761/month—$1,167 more than the fixed option.

When a Fixed Rate Makes Sense

Choose fixed if:

You're staying long-term. If you'll be in the home 10+ years, rate stability matters more than initial savings. Markets are unpredictable, and a rate spike in year 7 could cost more than you saved in years 1-5.

You're at your budget limit. If the fixed payment stretches your 28% housing ratio, you can't afford the risk of higher payments later. ARMs are for borrowers with room in their budget.

Rates are historically low. When fixed rates drop near historical lows, locking in makes sense. You're trading a small premium for certainty.

You value predictability. Some people sleep better knowing their payment won't change. That peace of mind has value.

When an ARM Makes Sense

Choose an ARM if:

You're selling within the fixed period. Moving in 4 years? A 5/1 ARM saves money without adjustment risk. The lower rate applies for your entire ownership.

You expect income growth. Early-career professionals often earn significantly more in 5-7 years. If higher future payments fit your trajectory, the initial savings compound.

You'll refinance before adjustment. If you plan to refinance into a fixed rate before the ARM adjusts, you capture the savings without the risk. This works when rates drop or your credit improves.

The rate gap is substantial. When ARMs are 1.5%+ below fixed rates, the math favors ARMs for shorter holding periods. At 0.5% difference, the risk rarely justifies the savings.

The Break-Even Calculation

To find when fixed beats ARM, calculate how long the ARM savings last versus potential rate increases.

Using our $400,000 example:

• Fixed payment: $2,594
• ARM payment (years 1-5): $2,366
• Monthly savings: $228
• Total 5-year savings: $13,680

If the ARM adjusts to 8% in year 6 ($2,889/month), you pay $295 extra monthly.

Break-even point: $13,680 ÷ $295 = 46 months

If you stay past year 9 (5 years + 46 months) with an 8% adjusted rate, the fixed loan wins. Leave before year 9, and the ARM saves money.

This assumes rates rise 2%+ at adjustment. If rates stay flat or drop, the ARM wins longer.

Current Rate Environment (January 2026)

As of January 2026, the gap between fixed and ARM rates is moderate—about 0.75% to 1%. This makes ARMs attractive for 5-7 year holds but less compelling than when gaps exceeded 1.5%.

Check current rates for your state, as regional lenders sometimes offer better ARM pricing.

Questions to Ask Your Lender

Before choosing an ARM:

1. What index does the rate adjust to? (SOFR is most common now)
2. What's the margin added to that index?
3. What are the initial, periodic, and lifetime caps?
4. Can I convert to a fixed rate later, and at what cost?
5. Is there a prepayment penalty if I refinance early?

Get these terms in writing. The lowest initial rate means nothing if the adjustment terms are unfavorable.

The Bottom Line

Fixed rates trade higher initial cost for certainty. ARMs trade lower initial cost for future risk. Neither is universally "better"—the right choice depends on your timeline, risk tolerance, and the current rate gap.

Use our calculator to compare actual payments with your loan amount and see how different rates affect your monthly budget.