how do you calculate power output from a push pull tube amp?

[ELS122]

I want to calculate the output power from a 6V6GT, 6L6GB, and 6F6 amps
they are all 2 tube push pull.
also I know you can use a load and calculate by voltage drop but I want to calculate it without actually having the amp
so can I calculate the power output by the tube specs or something?

[gbaddeley]

Yes, it is a percentage of the combined max continuous dissipation of the output tubes. The % varies depending on the +HT, and how the tubes are driven and biased (the Class). The output transformer will deliver (nearly all) of this power into the load, provided the correct anode load impedance is matched to the speaker load impedance.