How accurate are Zillow’s Zestimates?

General Tech Tools by Guy Johnson

[Ed. Note: A more recent blog post on this topic (published December 26, 2017) can be found here: How Accurate is Zillow’s Zestimate?]

This is a question I get asked frequently. ..and is one, the answer of which, Zillow is constantly monitoring, and makes readily available. Zillow computes its Zestimate accuracy by comparing the final sale price of a home to the Zestimate for that home on or before the sale date. And Zestimates are automatically computed three times a week.

So how accurate is Zillow’s Zestimate? From Zillow’s website:

Nationally, the Zestimate has a median error rate of 8%, which means half of the Zestimates in an area are closer than the error percentage and half are farther off. For example, in Seattle, Zestimates for half of the homes are within 6.6% of the selling price, and half are off by more than 6.6%.

Zillow makes public the Zestimate accuracy data for every state, county, and major metro area in the U.S. For example, here is the latest Zestimate accuracy info for Nevada. [Note: If you’re a data geek, Zillow even allows you to download to a spreadsheet.]

So how accurate are Zestimates for our local market? Drilling down to Washoe County from the link above, the most recent accuracy numbers are:

  • within 20% of the actual sales price 86.9 percent of the time
  • within 10% of the actual sales price 64.6 percent of the time
  • within 5% of the actual sales price 34.4 percent of the time
  • for an overall median error rate of 7.3 percent

What do these numbers mean? Zestimates for half of the homes in Washoe County are within 7.3% of the selling price, and half are off by more than 7.3%. One-third of the Zestimates for Washoe County homes are within 5% of the actual sales price, and about two-thirds are within 10% of the actual sales price.

That’s not too bad for an automated algorithm that has never seen the property. As Zillow states on it’s site:

[A Zestimate] is not an appraisal. It is a starting point in determining a home’s value…We encourage buyers, sellers, and homeowners to supplement Zillow’s information by doing other research such as: Getting a comparative market analysis (CMA) from a real estate agent.

So, if you’d like to get an idea of your home’s value, start with Zillow; but for a more in-depth analysis, give me a call — 775-722-4011 – or send me a note. I’d be happy to help.

For much more information on Zestimates, check out Zillow’s Zestimate FAQ page.

Related post: How accurate are Zillow’s Zestimates for our market? (March 3, 2012)

13 comments

  1. Jaymz

    Zillow was 99.9% accurate when it came to the sale of my condo last year. The estimate was $192k and it sold for $191,750.

  2. Jaymz

    I paid $135k for it in 2009, Not a bad profit considering I didn’t have to pay any income tax on the sale as I owned and lived in it for 5 years. Although being that I’m still bullish on Northern Nevada Real estate, I turned right around and paid cash for a beautiful home in Wingfield hills with gorgeous 180 degree panoramic views of the mountains and Red Hawk gold course. According to comparable sales, NOT zillow, it is already worth $18k more than I paid . No complaints here!

  4. Bob

    I am waiting for prices to drop

  5. Zen

    I sold my house last year. Zillow was less than 1% of the sale price. I interviewed two experienced realtors. Realtor 1 wanted me to put it on the market for 21% below what it sold for. Realtor 2, who got the listing, had me to put it on the market for 10% above what it sold for. Both of them had every oportunity to look at the house before giving me their suggested listing price. To be fair, the property is in an area of town with old custom built homes, so there are no direct comps to go by. In my case, I’d say Zillow did a pretty good job. I still wouldn’t completely trust it to list a property at though.

  6. Zen

    Bob, while I think home prices are ridiculous again so I don’t blame you, I’m just not sure that were going to see another big drop like the last one. What do you see down the road that makes you think we will?

  7. Bob

    Just as history as guide. I think they will take a dip, but don’t drastic drop. It’s been going up to high for too long now.

  9. Joe

    Good ol´Banaterin Bear.. Talking doom n gloom since the median price was $135k LOL

  10. Joe

    Reno could easily add 30% more houses to the current inventory and still have a balanced and healthy market. Unfortunately for BB this won’t be happening though.

  11. sestamibi

    While I don’t think Zillow or Trulia are useful for providing pin-point accuracy in estimating home values at any given time, they are good for tracking trends over longer periods of time. You might get a better estimate by multiplying the current Zestimate by the ratio of actual price to Zestimate at the time the house was last sold.

  12. Mike R

    I think Zillow is on the lower end of the selling price. Trulia is on the upper end of the selling price. We are ready to sell our rental home and have found a 40k difference between the both of them. We bought our current home in 2013 and the Zestimate is lower than what we paid for it by 5%. It recently appraised at the Trulia estimate. Like everyone is saying, it’s a good rough estimate at what your house will probably sell for.

Leave a Reply

Your email address will not be published. Required fields are marked *