(Pronounced ZEST-ti-met )
The Zestimate® home valuation model is Zillow’s estimate of a home's market value. The Zestimate incorporates public and user-submitted data, taking into account home facts, location and market conditions.
It is not an appraisal and it should be used as a starting point. We encourage buyers, sellers and homeowners to supplement the Zestimate with other research such as visiting the home, getting a professional appraisal of the home, or requesting a comparative market analysis (CMA) from a real estate agent. Read more
Zillow also provides a Rent Zestimate estimated monthly rental price. Learn more about the Rent Zestimate.
Zillow publishes Zestimate home valuations for 97.5 million homes across the country, and uses millions of statistical and machine learning models that can examine hundreds of data points for each individual home.
To calculate a Zestimate, Zillow uses a sophisticated and proprietary algorithm that incorporates data from county and tax assessor records and direct feeds from hundreds of multiple listing services and brokerages. The Zestimate also incorporates a home's facts and features, which homeowners have the ability to update.
The Zestimate accounts for variables like:
Home characteristics including square footage, location or the number of bathrooms.
Unique features like hardwood floors, granite countertops or a landscaped backyard.
On-market data such as listing price, description, comparable homes in the area and days on the market.
Off-market data — tax assessments, prior sales and other publicly available records.
Currently, we have data for over 110 million U.S. homes and we calculate Zestimates for more than 97.5 million of them.
How accurate is the Zestimate?
The Zestimate’s accuracy depends on location and the availability of data in an area. Some areas have more detailed home information available — such as square footage and number of bedrooms or bathrooms — and other areas do not. The more data available, the more accurate the Zestimate value will be.
The amount of data we have for your home and homes in your area directly affects the Zestimate's accuracy. If the data is incorrect or incomplete, update your home facts — this may affect your Zestimate.
To ensure the most accurate Zestimate, report all home updates to your local tax assessor. Unreported additions, updates and remodels aren't reflected in the Zestimate.
Check that your tax history and price history (the sale price and date you bought your home) are accurate on Zillow. If data is missing or incorrect, let us know.
I just listed my home for sale. Why did my Zestimate change?
When a home goes on the market, new data can be incorporated into the Zestimate algorithm. In the simplest terms, the Zestimate for on-market homes includes listing data that provides valuable signals about the home’s eventual sale price. This data isn't available for off-market homes.
I just changed my home facts. When will my Zestimate update?
Updates to your home facts are factored into the Zestimate. However, if the updates are not significant enough to affect the home's value, your Zestimate may not change. Zestimates for all homes update daily, but on rare occasions this schedule is interrupted by algorithmic changes or new analytical features.
How are changes to my home facts (like an additional bedroom or bathroom) valued?
The Zestimate is based on a complex and proprietary algorithm that incorporates millions of data points. The algorithm determines the approximate added value that an additional bedroom or bathroom contributes, though the amount of the change depends on many factors, including location and other home facts.
Can the Zestimate be updated?
Is the Zestimate an appraisal?
No. The Zestimate is not an appraisal and can't be used in place of an appraisal. It is a computer-generated estimate of the value of a home today, given the available data.
The Zestimate should not be used as the basis of any specific financial transaction because data sources may be incomplete or incorrect. The Zestimate is a starting point and does not consider all the market intricacies that can determine the actual price a home will sell for.
Why do I see home values for the past?
We use computing cycles to generate historical Zestimates. This allows you to see how a home (or an area) has changed in value over time.
Do you ever change historical Zestimates?
Yes. When major improvements to the algorithm are made, we may recalculate historical Zestimates for affected homes. This provides you with the best estimate of historical property valuations.
However, we never allow future information to influence a historical Zestimate (for example, a sale in 2019 could not influence a 2018 Zestimate valuation). Historical Zestimates only use information known prior to the date of that Zestimate.
Does the Zestimate algorithm ever change?
Yes — Zillow’s team of researchers and engineers work every day to make the Zestimate more accurate. Since Zillow's founding in 2006, we have deployed multiple major Zestimate algorithm updates and other incremental improvements are consistently released between major upgrades.
How often are Zestimates for homes updated?
We refresh Zestimates for all homes daily, but on rare occasions this schedule is interrupted by algorithmic changes or new analytical features.
Are foreclosure sales included in the Zestimate algorithm?
No. The Zestimate is intended to provide an estimate of the price that a home would fetch if sold for its full value, where the sale isn't for partial ownership of the property or between family members. Our extensive analysis of foreclosure resale transactions supports the conclusion that these sales are generally made at substantial discounts compared to non-foreclosure sales. For this reason, the Zestimate does not incorporate data about these sales.
Who calculates the Zestimate? Can someone tamper with my home’s Zestimate?
The Zestimate is calculated by an automated software process. It's not possible to manually alter the Zestimate for a specific property.
Does Zillow delete Zestimates? Can I have my Zestimate reviewed if I believe there are errors?
We do not delete Zestimates. However, for some homes we may not have enough data to provide a home valuation that meets our standards for accuracy. In these instances, we do not publish the Zestimate until more data can be obtained.
The Zestimate is designed to be a neutral estimate of the fair market value of a home, based on publicly available and user-submitted data. For this purpose, it is important that the Zestimate is based on information about all homes (e.g., beds, baths, square footage, lot size, tax assessment, prior sale price) and that the algorithm itself is consistently applied to all homes in a similar manner.
I don't know of any homes that have sold recently in my area. How are you calculating my Zestimate?
Zestimates rely on much more than comparable sales in a given area. The home's physical attributes, historical information and on-market data all factor into the final calculation. The more we know about homes in an area (including your home), the better the Zestimate.
Our models can find neighborhoods similar to yours and use sales in those areas to extrapolate trends in your housing market. Our estimating method differs from that of a comparative market analysis completed by a real estate agent. We use data from a geographical area that is much larger than your neighborhood — in fact, we often use all the data in a county to help calculate the Zestimate. Though there may not be any recent sales in your neighborhood, even a few sales in the area allow us to extrapolate trends in the local housing market.
I’m trying to sell my home and I think my Zestimate should be higher.
The Zestimate was created to give consumers more information about homes and the housing market. It is intended to provide user-friendly data to promote transparent real estate markets and allow people to make more informed decisions — it should not be used to drive up the price of a home. Zestimates are designed to track the market, not drive it.
Can I use the Zestimate to get a loan?
No. To get a federally guaranteed loan, a law called FIRREA (the Federal Institutions Reform, Recovery and Enforcement Act) requires you to get an appraisal from a professional appraiser. Lending professionals and institutions are prohibited from using other services when making any loan-related decisions.
I have two Zestimates for my home. How do I fix this?
If you see two Zestimates for the same property, please let us know by visiting Zillow Help Center and selecting Submit a request. You may see more than one Zestimate for your address if you are a homeowner with multiple parcels of land. Zillow matches the parcels on record with the county. If you officially combine parcels, the county will send us updated information.
What's the Estimated Sale Range?
While the Zestimate is the estimated market value for an individual home, the Estimated Sale Range describes the range in which a sale price is predicted to fall, including low and high estimated values. For example, a Zestimate may be $260,503, while the Estimated Sale Range is $226,638 to $307,394. This range can vary for different homes and regions. A wider range generally indicates a more uncertain Zestimate, which might be the result of unique home factors or less data available for the region or that particular home. It's important to consider the size of the Estimated Sale Range because it offers important context about the Zestimate's anticipated accuracy.
How can real estate professionals work with the Zestimate?
Millions of consumers visit Zillow every month. Most understand that the Zestimate is an estimate of the value of a home, and that it should be used as a starting point. When combined with the guidance of real estate professionals, the Zestimate can help consumers make more informed financial decisions about their homes.
We recommend that real estate agents and other professionals gain a basic understanding of how the Zestimate is calculated and how to read the Zestimate data accuracy table. This will help them explain to their clients why the Zestimate is a good starting point and historical reference, but should not be used for the final pricing of a home.
Real estate professionals can also help their clients claim their home on Zillow, update the home facts and account for any work they have done on the property. A home's Zillow listing is often the first impression for prospective buyers, and accurate information helps attract interest.