Inputs
Comparison summary
Trend chart
Yearly comparison
Notes
- Actual variable-rate contract rules differ by lender.
- This tool applies a simple reamortization model at each rate-change point.
- Use a refinance break-even model separately for fee-inclusive decisions.
FAQ
How is payment recalculated after a rate change?
At each rate-change point, payment is recalculated from the remaining balance and remaining term (reamortization model).
What does baseline comparison mean?
Baseline assumes the initial rate remains constant for the full term. Scenario results show how much total interest, total paid, and maximum payment increase.
Does this match every lender contract rule?
No. Lender-specific caps, reset windows, and payment limits vary. Use this as a comparison model, then verify contract details.
Can I use this before checking refinance options?
Yes. First estimate stress under higher rates, then compare refinance cost-recovery with a refinance break-even calculator.
Which mortgage values should I enter first?
Start with the current balance, remaining term, current rate, and the possible new rate. Then compare the payment and total-interest change before adding extra assumptions.
Mortgage rate scenario notes
What this simulator compares
The page recalculates payment and interest under a changed rate so you can estimate payment shock, renewal risk, or a refinance comparison baseline.
Keep the remaining term aligned
Use the remaining amortization period for the current loan, not the original loan term, when you want a like-for-like payment comparison.
Read payment and interest together
A lower payment can still cost more interest if the term is extended. A higher payment may reduce long-term interest if the term is shorter or extra principal is added.
What this does not model
It does not apply lender-specific caps, escrow changes, taxes, insurance, refinance closing costs, or prepayment penalties unless you include them separately in your scenario notes.
Decision workflow
Run the current case first, then change only the rate or term. If the result is close to your budget limit, compare it with refinance break-even, DTI, and cash-reserve checks before deciding.