Simulator
ARM adjustment simulator
In brief
Enter the figures from your own ARM disclosure and an index value to test. The simulator applies the margin and caps to show the rate and payment after the first two adjustments if the index stays at that value, plus the worst case at the lifetime cap. It assumes yearly adjustments after the fixed period. Every field starts empty.
Last reviewed against the primary sources listed below.
Fixed vs. Adjustable-Rate Guide · https://stevesloans.com/arm-adjustment-simulator.html · General education only; nothing you entered was stored.
How to read your result
The result steps through each adjustment using the index, margin and caps you entered, showing where caps hold the rate down and the highest possible rate.
- Each step: index plus margin, then caps.
- Capped: the cap limited the change.
- Ceiling: the lifetime maximum.
What to do next
Check your loan's actual caps on the Loan Estimate and the ARM disclosure.
Simplifications
- Assumes a 30-year amortization and yearly adjustments after the fixed period.
- Ignores floors and rounding rules.
ARM questions
How does an ARM adjust?
At each change date, the new rate equals the index plus the margin, limited by the caps. The simulator shows this from your inputs.