To do this, I used Zillow's own data and simply multiplied
the median Zestimate error percentage by the median sale price of homes to create the «typical» Zestimate error in dollars.
The median Zestimate valuation for a given geographic area on a given day is the Zillow Home Value Index.
The Zillow Home Value Index is
the median Zestimate valuation for a given geographic area on a given day.
We feel it is, because with the Zestimate, we have an estimate of the current value of every home in the area and, thus, can estimate what the median sale price of the whole area would be if every home were sold on the same day: It would approximately equal
the median Zestimate, or Zillow Home Value Index for that area.
The median Zestimate is much less sensitive to extreme values than the average Zestimate (here, «average» refers to the mean).
The Zillow Home Value Index is
the median Zestimate valuation for a given geographic area on a given day.
Not exact matches
The Zillow Rent Index is the
median Rent
Zestimate valuation for a given geographic area on a given day.
In 2016, the
median error rate for Zillow's
Zestimate ™ dropped from 8 percent to 4.5 percent.
«Overall, the
Zestimate is incredibly accurate — with a
median error rate of 4.5 percent — but occasionally human error does occur,» Zillow spokesman Viet Shelton said in a statement.
For comparison, the
median error for Zillow's
Zestimate of home values is greater than 8 %.
You can see from the table above that the accuracy varies from city to city but overall the
median error rate for all Zillow
Zestimates in the U.S. is 6.1 %, according to Zillow.
Zillow publishes the
median percentage error of their
Zestimates but I think it's a lot easier to think in dollars rather than in percentages.
Zestimates have a
median error rate of 4.3 % nationally.
So, if the
median error was 7.6 % and the
median price was $ 255,000 then the typical dollar error for
Zestimates in that county would be $ 19,380 (0.076 x $ 255,000 = $ 19,380).