Methodology
About our data
Every number on a RealCostIQ state guide comes from a named public source or a documented formula — never a guess. Here's exactly how each figure is built.
The short version
State guide figures come from public sources (Zillow, the Tax Foundation, Freddie Mac, the U.S. Census, and others — cited on every page) combined with a small set of published formulas (like Fannie Mae's 1–1.5%-of-home-value maintenance guideline). Data is refreshed quarterly. Nothing shown is a real quote — it's a starting point for your own conversation with a lender, agent, or contractor.
Where each number comes from
Median home price
Zillow Home Value Index (ZHVI), state and city level. This is a smoothed, seasonally adjusted measure of typical home values — not a simple average of listing prices.
Property tax rate
Tax Foundation's annual Property Taxes by State report, plus county-level rate data for the highest/lowest county figures. The "effective rate" is your actual annual tax bill divided by your home's market value — the number that matters for budgeting, as opposed to the nominal or assessed-value rate a county might advertise.
Homeowners & flood insurance
Insurance.com's annual rate analysis for homeowners premiums; FEMA-filed NFIP premium data for flood insurance. Both are statewide averages for a standard dwelling coverage level — your actual quote depends on your home's age, construction, claims history, and specific location.
Mortgage rate
Freddie Mac's Primary Mortgage Market Survey (PMMS), the industry-standard weekly average for a 30-year fixed-rate mortgage.
Maintenance reserve
Fannie Mae's published guidance that homeowners should budget roughly 1–2% of their home's value per year for upkeep and repairs, cross-checked against Bankrate's Hidden Costs of Homeownership study. This isn't a bill anyone sends you — it's money you set aside yourself so a failed water heater or roof doesn't become an emergency.
Utilities
U.S. Energy Information Administration (EIA) state-level residential energy expenditure data.
Price-to-rent ratio & break-even
Median home price divided by median annual rent for a comparable home. As a rule of thumb: below ~15 tends to favor buying, above ~21 tends to favor renting, and the break-even year estimates how long you'd need to stay for buying to cost less than renting once appreciation, equity, and transaction costs are factored in.
First-time buyer & down payment assistance programs
Pulled directly from each state housing finance agency's published program terms — income limits, purchase price caps, and assistance amounts. These change periodically; always confirm current terms with the administering agency before applying.
How "true monthly cost" is calculated
This is the core number behind every state guide — the one your lender's pre-approval letter doesn't show you. It's a straight sum of six components, each calculated at the state's median home price with 20% down:
- Mortgage principal & interest — standard amortization formula at the current Freddie Mac PMMS rate
- Property tax — median home price × the state's effective tax rate, divided by 12
- Homeowners insurance — the state's average annual premium, divided by 12
- Maintenance reserve — median home price × 1–1.5% per year, divided by 12
- Utilities — the state's average monthly residential energy expenditure
- HOA fees — included only when relevant, at the state's average single-family HOA fee
Add them up and you get the true monthly cost — a realistic estimate of what homeownership actually costs each month, not just the loan payment.
Update cadence
State data is refreshed quarterly. Each state guide shows its own "Updated" timestamp near the top of the page. Mortgage rates and home prices move faster than our refresh cycle in an active market — treat every figure as a well-sourced estimate for planning purposes, not a live quote.
What this data is — and isn't — for
Every figure here is a statewide or city-level average or median. Your actual costs depend on your specific property, county, lender, insurer, and credit profile. Use these numbers to build a realistic budget and ask better questions — not as a substitute for a real quote from a lender, insurance agent, or licensed professional before you make a financial decision.