PANZEUS Home Affordability Calculator
See how much house you can realistically afford in two views: a conservative 28/36 number and a stretched 31/43 FHA-friendly number, with the math shown for both.
Assumptions
Realistic defaults, still not the whole plan
Property tax default
1.1% of home value per year
Home insurance default
$2,200 per year
PMI default
0.7% of loan balance per year when down payment is below 20%
Closing cost estimate
3% of loan amount
How the math works
Conservative 28/36 rule
Industry rule of thumb: housing payment ≤ 28% of gross monthly income (front-end), total debt payment ≤ 36% (back-end). The conservative estimate uses these caps.
Stretched 31/43 (FHA-friendly)
FHA lender guidelines allow up to 31% front-end and 43% back-end. The stretched estimate uses these caps. Some lenders push to 50% back-end with compensating factors, but that is not modeled here.
Binding ratio
When existing monthly debts are high, the back-end ratio binds first and the maximum housing payment is reduced. When debts are low, the front-end ratio binds and the housing payment hits the 28% (or 31%) ceiling.
Reuses the mortgage assumptions
Property tax, insurance, PMI, and closing costs are shared with the mortgage calculator. Adjusting them in one place keeps both tools consistent.
Not a pre-approval
Lenders weigh credit score, employment history, reserves, and cash flow that this calculator does not see. Use the result as a planning anchor, not a guarantee.
Local taxes, insurance, HOA dues, credit score, lender fees, and future life events can materially change affordability. This calculator is an educational estimate, not financial, tax, legal, or lending advice.
Sources
CFPB guidance on DTI ratios used by lenders to assess affordability and qualify borrowers for mortgages.
HUD — FHA underwriting handbook
FHA Single Family Housing Policy Handbook 4000.1 specifies the 31/43 ratio limits used in the stretched estimate. Higher ratios may be approved with compensating factors.
Default 30-year fixed rate (6.23%) and 15-year fixed rate (5.40%) from the Freddie Mac Primary Mortgage Market Survey, the US benchmark since 1971.
Tax Foundation — Property taxes by state
Default property-tax rate of 1.1% reflects the US national average. Your state may run materially higher (NJ ~2.2%) or lower (HI ~0.3%).
Insurance Information Institute — Homeowners
Default annual home-insurance premium of $2,200 reflects the US national average. Coastal / wildfire-prone states (FL, CA, LA) typically run 2–3× higher.
What standalone tools miss
A mortgage is not just a payment. It changes the whole household timeline.
PANZE connects home buying with emergency funds, retirement, kids, education, insurance, taxes, and cashflow year by year. The free calculator gives you one clean answer. The app helps you understand the tradeoff.
Plan the whole picture with Penny.
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