A fixed-rate mortgage locks your interest rate for the entire loan term (15 or 30 years), providing predictable payments. An adjustable-rate mortgage (ARM) offers a lower initial rate for 5-10 years, then adjusts periodically based on market rates. Choose fixed for long-term stability; consider an ARM if you plan to move or refinance within the initial fixed period.
Bottom line:
Key Takeaways
- Fixed-rate mortgages: same payment for 15 or 30 years, no surprises
- 5/1 ARM: fixed rate for 5 years, then adjusts annually — often 0.5-1.0% lower initially
- ARMs carry risk: payments can increase significantly after the fixed period ends
- Most ARMs have rate caps limiting how much rates can increase per adjustment and over the loan life
- Choose fixed if staying 10+ years; consider ARM if moving or refinancing within 5-7 years
With a fixed-rate mortgage, your interest rate
With a fixed-rate mortgage, your interest rate and monthly principal-and-interest payment never change for the entire loan term. A 30-year fixed at 6.5% on $300,000 means your P&I payment of $1,896 stays exactly the same from month 1 to month 360.
This predictability makes budgeting easy and protects you from rising interest rates. The tradeoff is that fixed rates are higher than initial ARM rates — you're paying a premium for certainty.
Rate caps
ARMs have two phases: an initial fixed period (usually 5, 7, or 10 years) with a lower-than-market rate, followed by an adjustable period where the rate resets annually based on a market index plus a margin.
A 5/1 ARM means 5 years fixed, then adjusting every 1 year. A 7/6 ARM means 7 years fixed, then adjusting every 6 months. The initial rate is typically 0.50-1.00% lower than a comparable fixed rate.
Rate caps limit increases: typically 2% per adjustment, 5-6% over the loan's lifetime. A 5/1 ARM starting at 5.5% with a 5% lifetime cap can never exceed 10.5% — still high, but bounded.
Choose fixed-rate if
Choose fixed-rate if: you plan to stay 10+ years, you prefer payment certainty, rates are relatively low, or you're on a tight budget where payment increases would be stressful.
Consider an ARM if: you plan to move within the initial fixed period, you expect to refinance before the rate adjusts, you believe rates will decrease, or the rate savings are substantial enough to build a meaningful financial buffer.
On a $350,000 loan, a 0
On a $350,000 loan, a 0.75% rate difference between fixed (6.5%) and ARM (5.75%) saves about $170/month during the initial period. Over 5 years, that's $10,200 in savings. If you move or refinance before the ARM adjusts, you capture those savings with no downside risk.
If you stay past the fixed period and rates increase, your payment could rise by $200-$500/month or more. This risk is why most financial advisors recommend fixed-rate for long-term homeowners.
How We Evaluated
Rate examples based on typical Q1 2026 spreads between fixed and ARM products. Payment calculations use standard amortization.Frequently Asked Questions
Which option is better for most people?
It depends on your goals, risk tolerance, and financial situation. The article breaks down pros and cons so you can decide which fits best.
Can I use both options at the same time?
In many cases, yes. Using a combination can provide diversification. We explain when it makes sense to use both.
What are the main cost differences?
We compare all relevant fees, minimums, and costs. Total cost depends on usage and provider.
How do I switch from one to the other?
Switching is usually straightforward, though there may be tax implications. We outline the process and what to watch for.
Which is better for long-term goals?
Both have strengths for long-term planning. The best choice depends on your time horizon and tax situation.
Editorial Disclosure: WalletGrower may earn a commission from partner links. Our editorial content is independent and not influenced by advertisers. We research products independently and only recommend what we believe in. Updated April 2026.