In testing, the effective range of the Eero was 70 to 80 feet (21 to 24 meters), but the distance at which the signal remained strong was about half that. Generally it's tricky to find the right spot for a range extender. You need to put it relatively close to the existing router for it to have a good connection with the main network, but at the same time far enough away to maximize the extended the range. In the case of the Eero, I found that 40 feet was ideal if there were no obstacles between the two.