可调利率抵押贷款计算器 — 公式

Adjustable-Rate Mortgage (ARM)

An ARM starts with a lower fixed rate for an initial period, then adjusts periodically based on a market index plus a margin.

Common ARM Structures

  • 5/1 ARM: Fixed for 5 years, adjusts annually
  • 7/1 ARM: Fixed for 7 years, adjusts annually
  • 10/1 ARM: Fixed for 10 years, adjusts annually

    • Rate Caps

    ARMs have caps limiting rate changes:

  • Initial cap: Maximum first adjustment (typically 2%)
  • Periodic cap: Maximum annual adjustment (typically 2%)
  • Lifetime cap: Maximum over loan life (typically 5-6%)

    • When an ARM Makes Sense

  • You plan to sell or refinance before the fixed period ends
  • You want to maximize cash flow in the early years
  • You believe rates will stay stable or decrease

    • 计算示例

    A $400,000 loan. 5/1 ARM at 5.75% initial, expected adjustment to 7.75%. Comparable 30-year fixed at 6.75%.

    1. ARM initial payment (5.75%, 30-year amortization): $2,334.29
    2. Fixed rate payment (6.75%): $2,594.26
    3. Monthly savings during initial period: $2,594.26 - $2,334.29 = $259.97
    4. Total savings over 5 years: $259.97 x 60 = $15,598
    5. Balance at year 5: approximately $371,342
    6. Adjusted payment at 7.75% for remaining 25 years: $2,803.14