Fixed-Rate vs Adjustable-Rate Mortgage: Which Is Better?
Short answer. A fixed-rate mortgage keeps the same interest rate and principal-and-interest payment for the whole term. An adjustable-rate mortgage (ARM) starts with a lower rate for a set period, such as five years, then resets at intervals to follow a market index, so payments can rise or fall. Fixed buys certainty; an ARM buys a cheaper start.
Side by side
| Fixed-rate mortgage | Adjustable-rate mortgage (ARM) | |
|---|---|---|
| Interest rate | Constant for the whole term | Fixed at first, then adjusts to an index plus a margin |
| Starting rate | Usually higher | Usually lower |
| Payment predictability | Full for principal and interest | Uncertain after the initial period |
| Rate caps | Not needed | Caps limit each adjustment and the lifetime rise |
| Benefit if rates fall | Need to refinance to capture it | Payment can fall automatically |
| Risk if rates rise | None on this loan | Payment can rise, sometimes sharply |
| Typical fit | Long stays, tight budgets | Short stays, or expected income growth |
Which one fits you?
Lean towards Fixed-rate mortgage if…
- you plan to stay for many years
- you want a payment that never surprises you
- rates are low relative to history
Lean towards Adjustable-rate mortgage (ARM) if…
- you expect to sell or refinance before the first reset
- you can afford the payment at the capped maximum rate
Frequently asked questions
When does an ARM reset?
A ‘5/1 ARM’ keeps its rate for 5 years, then adjusts every year. The first number is the fixed period, the second is how often it adjusts after that.
What is a rate cap?
A limit on how much the rate can rise at each adjustment and over the life of the loan. Check the periodic and lifetime caps before signing.
Can I refinance an ARM into a fixed loan?
Usually yes, if you qualify and the costs make sense, but it depends on rates and your credit at the time.
General education, not personal financial advice. Figures are typical US examples and vary by provider and year.