The salary-needed layer in Explore answers a specific question: what gross income would keep modeled housing costs at 28% of income? It does not tell you what a lender will approve or what you can comfortably spend. It covers counties with the necessary saved inputs; missing counties are not free or affordable.
Reproduce the calculation
- Take the county's stored home value and subtract a 20% down payment.
- Calculate principal and interest on the remaining 80% using a 30-year loan at a fixed 6.5% annual rate.
- Add the stored annual property-tax amount divided by 12. Where tax data are absent, the model substitutes 1% of home value annually.
- Add insurance at an assumed 0.5% of home value per year, divided by 12.
- Multiply the monthly total by 12 and divide by 0.28.
The loan-payment formula is P × r × (1+r)^360 / ((1+r)^360 − 1), where P is the loan balance and r is 0.065/12. The interest rate and insurance percentage are assumptions, not current quotes.
A worked example you can check
For an illustrative $300,000 home, the down payment is $60,000 and the loan is $240,000. Principal and interest are about $1,517 per month. Assuming $3,600 annual property tax adds $300; assumed insurance adds $125. Total modeled housing cost is about $1,942 monthly. Dividing its annual total by 28% gives roughly $83,228 in gross annual income. Rounding intermediate payments can change the last few dollars.
This example excludes HOA dues, maintenance, utilities, closing costs and existing debt. If those add $500 monthly to your household budget, the model's headline does not make that expense disappear. A lower down payment changes the loan and can introduce mortgage insurance, which this county scenario does not model.
What the county value represents
Zillow's Home Value Index describes typical estimated home values. It is not a median sale price, an appraisal of your prospective home, or an available listing. The county snapshot and tax inputs may cover different periods. A county-wide number also combines housing that may not match your required bedroom count or location.
Turn the map into a personal budget
Choose a candidate county, then use a specific listing and an actual loan quote in the mortgage calculator. Obtain tax and insurance estimates for that property. Keep the down payment and closing cash separate from your recurring monthly budget. Finally, test whether the budget still works with your debts, childcare and emergency reserve.
The CFPB home-buying resources explain the loan-shopping process. Our methodology explains the site's saved datasets. The earlier article's county rankings and claims of an exact required salary have been removed because they were not reproducible from a documented current snapshot.