Does anybody know the transmit power of a Draytek access point in dB? When set to 100%

One set of figures, for the AP802:-

In the AP802 Quick Start Guide, Draytek wrote: 5G WLAN 5160 - 5340 MHz, max. TX power : 22dBm
5480 - 5720 MHz , max TX power : 29dBm

ISTR that the AP903 is 29dBm across the entire band. (The AP802 transmit power on the 2.4GHz band is 19.96dBm).
I assume these numbers can be compared across Draytek's product range - but do all manufacturers measure them in the same way?

Reading this: https://www.digitalairwireless.com/articles/blog/wifi-transmit-power-calculations-made-simples , it seems that 1 Watt is the maximum that is allowed. This is probably easily achieved in a mains powered AP, but I wonder what the average transmit power of the average wifi client (e.g. phone) is?