Listimate™ vs. Zestimate – What’s Your True Home Value?

Updated April 14, 2025

Today, we’re going to be clarifying the difference between a Comparative Market Analysis and a Zestimate. It’s well known among real estate agents, real estate appraisers, mortgage lenders, and other professionals in the business that good old Zillow’s “Zestimates” of home values are wrong.

I know! That’s a pretty strong statement. But I wanted to get your attention. So now that I have it, I will correct myself. Zestimates are not always wrong. However, I would put them wrong about 99+% of the time. Once in a while, they can be accurate. When you put out millions and millions of Zestimates, you’re going to hit one right once in a while.

(Just in case you don’t know, a “Zestimate” is an automated estimate of your home’s value from the real estate site, Zillow.com.)

Zillow is a wildly successful website offering a lot of good information to a lot of good people. But even Zillow admits and states on the website that Zestimates may not be accurate. Most people never see that though and just assume they are as accurate as professionally prepared appraisals, and CMA’s.

It’s very confusing and frustrating to people when we are invited to their house to discuss listing their home for sale and we get to the part where we talk about the market value of the property and our estimate, which is called a Listimate™, based on a CMA (for comparative market analysis), is very different than the one they saw on Zillow. You can imagine how they’re especially frustrated if the Zestimate was a higher number than our Listimate™. That’s only natural. The seller prefers a higher market value.

Listimate™ vs. Zestimate

So, you ask; “What’s the difference between appraisals, CMAs, Listimates™, and Zestimates? Why are Zestimates not as accurate?”

I think the best way to start the explanation is by stating that preparing an accurate estimate of a home’s market value is both an art and a science. Zestimates are created by science only. Appraisals and CMA’s use both art and science.

Appraisals are created by a neutral third-party company for the lender to make sure the loan amount requested for the home mortgage accurately represents the value of the home.

A CMA is typically done by a licensed real estate agent or Realtor. How the CMA is done depends on the particular agent. Each agent has their own method and experience when it comes to determining the true value of a home. Some of the things that influence an agents method include: how much experience the agent has, how well does the agent know the area, how well does the agent know the neighborhood, is the CMA being done for general purposes, or are they determining the value of the home today for the purposes of listing the home for sale?

This is how Zestimates are created. Zillow’s system is an automated one. That’s important. Using enormous amounts of data collected from public records, such as the sales price of the home the last time it sold, what all the homes in the county sold for the last time they sold, county tax collector’s assessed value, and data like home features entered by the homeowner on the Zillow site, their secret algorithms come up with the Zestimate.

As you can see, Zillow has data to crunch scientifically but does not “know” important information that helps determine an accurate market value. Also, the data used can be flawed or irrelevant. If a home last sold 10 years ago, that info is not relevant today. Tax assessment values are created for purposes of tax collection and are not intended as the current market home values and are far from it.

County records will often have mistakes that Zillow cannot know, such as showing a house has 3 bedrooms when it really has 4.

Also, Zillow focuses on countywide data for comparisons of data rather than specifically defined neighborhoods. That data will include much that is not really comparable to the house under consideration. Especially in a large and diverse area such as Contra Costa County.

Here’s a very short list of some things that with all its data collection, Zillow does not know about your house:

It does not know if your kitchen was just upgraded.

It does not know if there is a major structural problem with the house.

It does not know if the roof needs to be replaced.

It does not know if you just replaced the roof!

It does not know there is a security system, or a surround sound system, etc.

You get the idea.

Wouldn’t you say these unknown things are important to the market value of the house? These and other unknown things are what separates Zestimates from CMA’s.

Why You Should Rely on a Real Estate Professional for Your CMA

The knowledgeable and experienced real estate agent uses plenty of accurate data available to the profession which is not available to Zillow and a thorough knowledge of the area to combine the art with the science necessary to come up with a much more accurate market value for the property.

The agent will use information about comparable properties in the right neighborhood rather than come up with a number based on all the houses in the county.

The agent will investigate and note issues like roof condition, structural problems, kitchen upgrades, etc.

The agent will know information about schools, parks, shopping, and lots of other area information that are important to the home value.

The agent can factor in all of these and more to come up with a much more accurate market value.

There is a lot of other information on Zillow that can be very helpful to buyers and sellers. Just about everything except for the Zestimate that is.

We find that once our clients understand the difference, they can sometimes become a bit down on Zillow. Some people even feel that an inaccurate Zestimate can and does cause them harm. One home seller in the Chicago area is even suing Zillow over a very low Zestimate that the seller believes potential buyers are seeing and then passing on the home because they think the asking price is too high.

Have you used Zillow or thought about using it to find out what your home is worth in today’s market? Would you like a much more accurate estimate at no cost or obligation to you? Good news! We can do that for you! We do it all the time and have been for over 25 years. Not only that, we are very happy to do it!

So, what is a Listimate™?

Our proprietary Listimate™ system has been developed over the years to accurately estimate the true market value of a property. Libby and I developed this system over our combined 50+ years of real estate experience, along with constant education about the market, along with listing and selling over one thousand homes during our careers.

If you would like a professionally prepared Listimate™ for your house, just call us at 925-628-2436 or just Find out how much Your Home is Worth.

Oh, by the way, if you know someone who would like to find out how much their home is valued, please consider sharing this article with them using the share buttons below.

Thanks!