How does Zillow calculate housing values?

[Katharine Chartrand]

How does Zillow calculate housing values?

[Gualter Amarelo]

In one word it's, "MAGIC".

Honestly I don't know the details of their algorithm, but I can guarantee it is based partially around the following 2 things, recent sales and tax assessments.

More important is how accurate are these Z'estimates? In my experience they have been pretty much dead on except in a few instances with outliers and houses with functional obsolescence.

For instance, I sold my first house  a little over a year ago. 

Zestimate: $203k

Listed: $220K

Sold for: $205K

Hope this helps!