Mortgage Stress Test Calculator
e.g., spouse loses job
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How to use
- 1 Enter your gross monthly income (combined for dual-earner households).
- 2 Enter total monthly debt minimums (auto, student, credit cards, alimony) — same as standard DTI.
- 3 Enter the home price and your planned cash down payment.
- 4 Enter the quoted 30-year rate (Freddie PMMS averages around 6.30% in early 2026), property tax rate (US average 1.10%), and annual home insurance (US average $2,802/yr).
- 5 Set your income-drop scenario (25% = one earner reduced; 50% = job loss). Click Calculate to see all five stress scenarios side-by-side.
About Mortgage Stress Test Calculator
FAQ
Q What is a mortgage stress test in the US?
A self-applied risk check that re-runs your DTI under bad scenarios: rate hikes (+1%, +2%), income loss (25%, 50%), or both combined. Unlike Canada, the US doesn't mandate stress tests on fixed mortgages — but ARM borrowers are stress-tested at the fully-indexed rate by federal CFPB rule.
Q Should I qualify at the rate I'm offered or a higher rate?
For 30-year fixed loans, you qualify at the offered rate. For ARMs, lenders must qualify you at the fully-indexed rate (index + margin) under CFPB Ability-to-Repay rules. Smart buyers run a personal stress test at +1% and +2% to make sure they can refinance or absorb future rate increases.
Q How much should I keep in reserves for a mortgage?
Most underwriters want 2-6 months of PITI in reserves. Smart owners keep 6-12 months — enough to ride out a job search and avoid forced selling in a down market. FHA requires 1 month for 1-2 unit properties; Fannie wants more for jumbo or investment.
Q What rate increase should I stress-test?
Run +1% (mild Fed tightening) and +2% (aggressive tightening — 2022-2024 was +5%). For 5/1 or 7/1 ARMs, also stress-test the lifetime cap (often start rate + 5%) since that is the worst case for adjustment periods.
Q How do I stress-test for job loss?
Drop one earner's income to zero (or to expected unemployment benefits, typically 50% of wages capped weekly). Recompute DTI on remaining household income. If back-end DTI exceeds 50%, you're too thin — hold more reserves or buy less house.
Q What is the 28/36 rule for mortgages?
A classic affordability guideline: front-end DTI (housing) ≤ 28% and back-end DTI (all debt) ≤ 36%. It's tighter than modern lender DTI caps (50%+) but it's the threshold below which most households can absorb shocks without distress.
Q Does property tax escalation matter for stress testing?
Yes. US property taxes are reassessed annually or biennially in most states; Texas, Florida, and Nevada have seen 10-30% jumps in single years. Stress-test PITI assuming property tax grows 5-7% per year — your monthly escrow can rise even on a fixed-rate loan.
Q What if I fail the stress test?
You have four levers: (1) larger down payment (lowers loan and PITI), (2) lower price target, (3) pay off consumer debt before applying, (4) extend loan term to 40 years (some non-QM lenders) to reduce monthly. Buying less house at lower DTI is almost always the best move long-term.
Official resources
CFPB — Adjustable-Rate Mortgages Explainer
Consumer Financial Protection Bureau official guide to ARM payment shock and how lenders qualify at the fully-indexed rate.
Freddie Mac — Primary Mortgage Market Survey (PMMS)
Weekly 30-year fixed average rate — the benchmark used to set base assumptions for stress testing.
CFPB — Ability-to-Repay & QM Rule
Federal regulation requiring lenders to verify ability to repay; defines QM safe harbor at 43% DTI and ARM stress test methodology.
OCC — Mortgage Lending Comptroller's Handbook
Office of the Comptroller of the Currency manual on residential mortgage risk assessment and underwriting standards.