Finance · 7 min read

7/1 ARM vs 30-Year Fixed Mortgage

A **7/1 ARM** fixes the rate for seven years then adjusts annually—lower start rate if you sell or refi before adjustment. A **30-year fixed** locks the payment for the full term—better when rates are low or you keep the home decades.

Step by step

1. Model year 8 payment

Use ARM caps (often 2/2/5) for worst-case adjustment.

2. Compare 7-year interest

ARM wins if you move before the reset window.

3. Stress higher rates

If still owning in year 8, fixed may have been cheaper.

7/1 ARM vs 30-year fixed

Average U.S. tenure is ~8 years—ARMs align for some movers.

  • 7/1 ARM: Lower initial rate; adjustment risk after year 7.
  • 30-year fixed: Payment certainty; higher starting rate.

Common mistakes

  • Assuming you will refi on time
  • Ignoring PMI on both options

FAQ

Can ARM rates drop?

Yes if the index falls—check floor on your note.