Questions and answers
ARM calculator FAQ
The calculator estimates principal and interest for ordinary, fully amortizing adjustable-rate mortgages. These answers explain what goes into the estimate and where its limits are.
Will this match my servicer’s payment exactly?
It may be very close when the balance, scheduled principal-and-interest payment, rate, remaining term, adjustment timing, index, margin, rounding rule, and caps match the servicer’s records. Posting dates, curtailments, contract details, and servicer timing can still create differences. The servicer’s notice and your note control.
Does the calculator predict the future index?
No. You choose an index value to test. The result is a scenario, not a forecast. The separate stress path assumes the index stays high enough to push the rate upward whenever the note permits.
Should I enter my total mortgage payment?
No. Enter principal and interest only. Leave out escrow, property taxes, homeowners insurance, mortgage insurance, HOA charges, late fees, and other amounts.
What if I do not know my current principal-and-interest payment?
The calculator can estimate it from the current unpaid balance, current rate, and payments remaining. Entering the scheduled principal-and-interest amount from your statement is preferable when it is available.
What is the difference between a first cap and periodic cap?
The first cap applies only at the first adjustment. The periodic cap applies to later adjustments and is measured from the rate immediately before each change.
Why is the lifetime-ceiling payment not my next payment?
A periodic cap may prevent the rate from reaching the lifetime ceiling at the next change. The calculator advances the rate and balance one adjustment at a time to show when the ceiling could become reachable.
What does “No cap” mean in the form?
It means the note does not set that particular limit. It is different from entering zero, which means the rate cannot move in that direction. Do not choose “No cap” merely because you do not know the answer.
Can this calculate an interest-only ARM?
No. Interest-only periods change both balance projection and payment calculation. The calculator stops rather than presenting a fully amortizing estimate that would not describe that loan.
Does it include taxes and insurance?
No. Every payment shown is principal and interest only.
Can I use it for a loan I am considering?
Yes. New Loan mode begins at origination and projects the balance through the initial fixed period before calculating the first adjustment.
Is this financial advice?
No. It is an educational calculation tool. It does not recommend a loan, refinancing decision, or financial strategy.