Adjustable-Rate Mortgage Reset Payment Calculator

Project the payment shock when an adjustable-rate mortgage resets. Enter the remaining balance, months left on the amortization schedule, current APR, and expected reset APR to compare monthly payments side by side, highlight the percent change, annualize the cash impact, and confirm how much of the shift comes from the rate jump versus the time left on the loan.

Outstanding loan balance on the adjustment date, excluding escrow items.
Number of monthly payments remaining in the amortizing schedule.
Current annual percentage rate before the next reset takes effect.
Projected annual percentage rate immediately after the reset.

For planning purposes only. Confirm payment details, rate caps, and adjustment math with your mortgage servicer before relying on the results.

Examples

  • $320,000 balance, 300 months remaining, 3.25% current APR, 5.75% reset APR ⇒ New monthly payment: $2,013.14 • Current monthly payment: $1,559.41 • Monthly change: $453.73 (increase) • Monthly change percentage: 29.10% • Additional annual cash flow: $5,444.76 • Remaining amortization term: 25 years • Rate change: +2.50%
  • $420,000 balance, 240 months remaining, 2.90% current APR, 4.40% reset APR ⇒ New monthly payment: $2,689.44 • Current monthly payment: $2,261.73 • Monthly change: $427.71 (increase) • Monthly change percentage: 18.91% • Additional annual cash flow: $5,132.52 • Remaining amortization term: 20 years • Rate change: +1.50%

FAQ

Does the calculator include periodic or lifetime rate caps?

Rate caps vary by lender, so the tool assumes the reset APR you enter already respects those limits. Run multiple scenarios using the cap values from your note to see best, base, and worst cases.

How can I model an interest-only period before amortization resumes?

Set months remaining to the count of amortizing payments that begin after interest-only ends, then enter the post-reset APR so the payment reflects the new fully amortizing phase.

Can I add escrow items like property taxes or insurance?

Escrow items differ by borrower and state. Add the monthly escrow amount you receive from your servicer to the calculated payment if you budget using PITI totals.

What if my margin is tied to an index like SOFR or the 1-year Treasury?

Estimate the upcoming index value, add your contractual margin, and enter the combined APR as the reset rate. Update the scenario whenever the index outlook shifts.

Additional Information

  • Calculations assume a fully amortizing loan with level monthly payments across the remaining term and no additional principal prepayments.
  • If the reset APR drops below the current APR, the calculator labels the payment difference as savings and annualizes the reduction.
  • Rate change is expressed in percentage points, while the monthly change percentage compares the payment difference to your current payment.
  • Escrowed property taxes, insurance, HOA dues, or mortgage insurance premiums are not included in the projected payment.
  • Results do not factor in future adjustments after the upcoming reset—rerun the scenario for each scheduled adjustment window.

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