When assessing the power emitted from a Wi-Fi network, it has been observed that these networks operate at a relatively low duty cycle. In this paper, we extend a recently introduced model of emitted power in Wi-Fi networks to cover conditions where devices do not always have packets to transmit. We present experimental results to validate the original model and its extension by developing approximate, but practical, testbed measurement techniques. The accuracy of the models is confirmed, with small relative errors: less than 5–10%. Moreover, we confirm that the greatest power is emitted when the network is saturated with traffic. Using this, we give a simple technique to quickly estimate power output based on traffic levels and give examples showing how this might be used in practice to predict current or future power output from a Wi-Fi network.