Methodology
Where our numbers come from.
Every figure on Home Value Pros traces back to a recognized public data source. This page explains each source, how we use it, and the limits of what an automated estimate can tell you.
Last reviewed July 15, 2026
Sources at a glance
| Source | What it provides | Cadence |
|---|---|---|
| Zillow ZHVI | Typical home values and value trends for about 26,000 ZIP codes, plus cities, metros, and states | Monthly release |
| Realtor.com | Listing activity: median list price, days on market, active inventory, price cuts, new listings | Monthly release |
| FRED (Freddie Mac PMMS) | National average mortgage rates | Weekly release, ingested at our monthly refresh |
Home values
Typical home values and value trends come from the Zillow Home Value Index (ZHVI), a smoothed, seasonally adjusted measure of typical home value published by Zillow at the ZIP code, city, metro, and state level. We track roughly 26,000 ZIP codes nationwide. ZHVI reflects the typical value for homes in the 35th to 65th percentile range of a market, which makes it a good anchor for what a representative home in an area is worth.
Market metrics
Listing-side market metrics come from Realtor.com residential listing data, including:
- Median list price
- Median days on market
- Active inventory (homes for sale)
- Share of listings with price cuts
- New listings entering the market
These describe the supply side of a market: how much is for sale, how fast it moves, and how often sellers adjust price. They complement ZHVI, which describes value.
Mortgage rates
National average mortgage rates come from the Freddie Mac Primary Mortgage Market Survey (PMMS), accessed via FRED, the Federal Reserve Bank of St. Louis economic data service. Rates shown are national averages and the rate you are quoted by a lender will differ based on your credit, loan type, and market.
Property tax and insurance estimates
Where we show estimated ownership costs, effective property tax and homeowner insurance figures are derived from the U.S. Census Bureau American Community Survey (ACS), which reports median real estate taxes and housing costs by area. These are area-level estimates, not quotes for a specific property.
Loan limits
Conforming loan limits come from the Federal Housing Finance Agency (FHFA), and FHA loan limits come from the U.S. Department of Housing and Urban Development (HUD). Both are published annually by county.
How our value estimates work
The estimated value we show for an individual home is produced by an automated valuation model (AVM) that starts from the ZIP-level typical value (ZHVI) and adjusts for the property's known attributes on record, such as beds, baths, and living area, relative to typical homes in that ZIP. Because no automated model can see the inside of your home, its condition, or its unique features, we present the estimate as a range rather than a single number.
An automated estimate is not an appraisal. It is not an offer to buy and it is not a promise of value. Actual value is determined by current market conditions and professional evaluation. If you need a definitive number for a sale, refinance, or legal purpose, get an appraisal from a licensed appraiser or a comparative market analysis from a licensed local agent.
We do not yet publish our own error rates. Once we have enough closed sales to measure them credibly, we will publish them on this page rather than quote an industry number we cannot verify.
Update cadence
We refresh our data monthly, after each source publishes its latest release. Each market page notes the as-of date for the figures it shows. Because sources publish on their own schedules, the most recent month shown can lag the current calendar month by several weeks.
Corrections
If a number looks wrong, tell us at hello@homevaluepros.com. We investigate every report and correct errors in the next data refresh. Full source attributions are listed on our data licenses page.
Our news articles follow a separate editorial policy covering AI-assisted drafting, sourcing standards, and corrections.