How the affordability tracker works

Data sources

• 30-year fixed mortgage rate: Federal Reserve Economic Data, series MORTGAGE30US (Freddie Mac Primary Mortgage Market Survey). We use the monthly average of the weekly readings for the snapshot month, and the latest weekly reading for the current-month tile until the month is complete.
• Statewide median home price: Zillow Home Value Index for Single-Family Homes, 2025 statewide annual medians, rounded to the nearest one thousand dollars. Refreshed annually or whenever the underlying ZHVI table shifts materially.
• Statewide median household income: U.S. Census Bureau, American Community Survey 2023 5-year estimates, table B19013, rounded to the nearest one thousand dollars. Refreshed annually as new ACS releases land.

Payment formula

The estimated monthly payment is a standard principal, interest, taxes, and insurance figure with documented assumptions:

• Loan amount equals 80% of the statewide median home price (20% down).
• 30-year fully amortizing fixed-rate amortization.
• Property taxes assumed at 1.0% of price annually (a national rough average; actual rates vary widely by jurisdiction).
• Homeowners insurance assumed at 0.35% of price annually (a national rough average; actual premiums vary by carrier, deductible, and risk profile).

The "payment as percent of income" figure divides the annualized monthly payment by the statewide median household income. Economists generally consider any household paying more than 30% of income on housing to be cost-burdened.

Refresh cadence

The 30-year rate input is refreshed every six hours from FRED. A new snapshot row is written for every state for the current calendar month, and re-runs within the same month overwrite the row in place. Median price and median household income are refreshed annually as new public data lands.

Trailing 24-month trend

The trend chart on every state page uses the monthly-averaged 30-year fixed rate from FRED for each of the past 24 months, applied to the current statewide median price and income. This isolates the affordability impact of rate moves and is the same approach used by most public affordability indexes. It does not back-project historical home prices or incomes.

What this is not

These figures are not a quote, an offer, an advertisement of a specific rate, or a representation of any rate, payment, or program available to any individual borrower. They are not personalized advice. Your actual rate and monthly payment depend on your credit, down payment, property type, occupancy, loan program, and the day you lock.