Mortgage Planning
Income Shock Mortgage Affordability Scenario
This guide shows how to model a lower income, see the impact on DTI and default probability, and compare a reduced-income run with your baseline without guesswork.
Published: January 1, 2026 · Updated: January 1, 2026 · By FinToolSuite Editorial
Open the stress tester
Run baseline and reduced-income scenarios, then compare outputs.
Disclaimer
- Educational only. Examples are illustrative. No guarantees.
- Results depend on inputs, assumptions, and randomness.
Modeling a lower income
Save your baseline scenario, duplicate it, reduce income (for example -20%), rerun, and compare outputs to see how DTI tails and default probability respond.
Illustrative example
Baseline income $10,000/month. Reduced scenario $8,000/month (-20%). With the same costs, DTI mid percentiles rise and the 90th percentile widens; default probability may tick higher. The recommended safe loan can move lower.
Safety notes
- Keep assumptions the same across scenarios to isolate income changes.
- Label scenarios clearly with dates and percentages.
- Use conservative rounding if income is uncertain.
FAQs
Should I change debts too?
Keep debts the same when testing an income change to isolate its effect.
How often should I rerun?
Rerun when your income changes. Note the date in the scenario label.
Is there another planning tool?
Try the income shock survival simulator for non-mortgage planning.
Where is privacy info?
See Privacy Policy before sharing exports.
Test an income drop
Open the mortgage affordability stress tester, run baseline and reduced-income scenarios, and compare outputs.