What is the range for an Airport Express?

The range of the AirPort Express is about 150 feet or 50 meters. But, this measurement is taken in free air, with no obstructions like walls or ceilings in the signal path, and no other networks in operation that might interfere with the wireless signal.

In the real world, in a real home, once the signal passes through 3-4 walls, it is about gone. A ceiling will absorb more of the signal than a wall, because it is thicker. So, as much as possible, you want wireless devices to have line-of-sight with the wireless router for best performance.

Bottom line....it is not possible to predict wireless performance in advance of any installation since there are so many variables involved.

Surprisingly, Apple specifications are literally the same for the AirPort Extreme in terms of distance.

There is a newer version of the Extreme that just started to ship about a month ago, that may provide a bit better distance capability due to a new antenna design. But, we'll have to wait for test reports to know if this is measurable improvement.