Zillow's Zestimate is one of the most popular online tools for homeowners to utilize to discover the value of their homes.

But how accurate is a Zestimate, and precisely what is it based on? Here is what you should know before using Zillow's Zestimate. 

What is a Zillow Zestimate?

A Zestimate is an estimated market value for a home that Zillow offers. This tool produces an online estimate for U.S. homes. Zillow depends on submitted data to deliver the estimates. The accuracy hinges on how much data is available. For example, if Zillow cannot determine how many bathrooms a house has, it affects the estimate's accuracy. 


Although any estimator tool is a good place to begin the search for your home's value, working with a real estate professional will always give you the most accurate value.

How is a Zillow Zestimate Calculated?

Zillow Zestimates are automatically calculated using an algorithm that considers multiple data points about each property, including recent sale prices, public tax assessor data, and listings data from partners. 

The algorithm is constantly refined to become more accurate over time. Users can manually adjust their Zestimate by providing information about their property, such as square footage, number of bedrooms and bathrooms, etc. 


The goal of the Zestimate is to give users a starting point for estimating a home's value. However, it is essential to remember that it is only an estimate and that a professional appraisal may be necessary to get a more accurate assessment of your home's worth.

How Accurate is a Zillow Zestimate?

According to Zillow, "The nationwide median error rate for the Zestimate for on-market homes is 3.2%, while the Zestimate for off-market homes has a median error rate of 7.52%. The Zestimate's accuracy depends on the availability of data in a home's area. Some areas have more detailed home information available — such as square footage and number of bedrooms or bathrooms — and others do not. The more data available, the more accurate the Zestimate value will be." 


It is important to remember that Zestimates are just estimates. They can be affected by several factors, including recent home sales in the area, property changes, and public record inaccuracies. 

How Can You Update Your Zillow Zestimate?

If you want to update your Zillow Zestimate, go to the website and create an account. 

Once you have verified your identity, you can edit your property information; this includes details like how many bedrooms you have, what kind of remodeling has been done, and square footage. 

Zillow uses public tax records as the basis for their off-market Zestimates, so it is important to have your information up-to-date and accurate. 

The Bottom Line

Although you can update your Zestimate, there is no promise that your property will be valued correctly.

Instead of using a computer algorithm, your best bet is to work with a real estate professional familiar with your community. 

The Glass House Real Estate Team

The Glass House Real Estate Team

We are passionate about empowering home buyers and sellers. Our team brings a wealth of knowledge and experience. We will help you seamlessly navigate the home buying or selling process stress-free.