Zillow Values for a duplex

[Garen T.]

I own a duplex that I purchased new. I have a pretty good idea of what it is worth, but I'm trying to reconcile that with what Zillow is reporting. It is a duplex with just one address in zillow but is for both units. However, Zillow shows the details as just one unit. It shows the address as a 3 bedroom and 2.5 bath at 1650 square feet. If Zillow show the value of the unit as $400K, would the actual "Zillow" value of the duplex be 2X that amount? That seems REALLY high.