Ayone know the wattage used at a Rock concert?

I could (and sometimes did) hook my trust A7s to my KLH Model 20 (the one without the tuner) compact system that had a mighty 24 watts or so per side, and it sounded great. For years we used a biamp thing made by Kustom (a non tuck and roll item) that had 200 watts for the bass bins and 100 for the horns…worked great and certainly shredded some ear balls.

yes, i used to do work for sound people here at madison squear garden and the Nassau collesium in the 70-80s. it was not unusual to run 150,000 to 400,000 back then. and i know it just kept getting bigg all the time, i used to save the smoked amps take em home and fix em. still got them tpoday. Crown was one of the biggest used, BGW, even Dynacos.Banks of amps with a few speakers each bank would be stacked and parralleled till you could run a freq sweep at 130db clean. most of this was called the pa which is nothing more than miking and distributing the bands own custom sound from local on or behind stage rack of their "rig" only the drummer didnt have his own rig and could be direct miked to the pa. this is also the system the big mixing board in the middle of the audience ran. they would almost NEVER mess with the bands rig setups. bid fistfights would result from rodies to the union arena guys. I even worked with "The Limelight" in NYC in the 80s and it had 300kw. mostly crown 10Kw 3 phase amps. i took a dew old ones and ran tig welding off the hurt outputs. at 150 amps . anyway the DI boxes are getting big but the rig is still king in the rock world.    "Sex,drugs,rock and roll"

In the early period, Metallica, played around 140db in concert.

not really, i used to carry around my spl calibrate meter and it depends on the weighting used and where you measure it. since in big venues the phase cancelling is a huge problem. the only reasonable area were the mics placed front of house near l an r of the mix board ofted used when recording the live stuff. yea they had all the individual feeds on separate tracks for later but it often went unsaved. i got a main board R to R 10" tape from Led  Nassau Colisum in 77. it had 8 tracks on a 1/2" and was a duplicate so i traded some party goodies for it. I also got a tape from the making of black and blue around 80 nassau collisium also. Ozzy even signed it. and i fell on him caus i was"sick" at the time.  you can really have fun nowadays with all the wireless Nadys and such. record your own direct feeds from the bands belt wireless transmitters. so many use similar off the shelf setups and run default freqs.
Ive heard a marshall stack in the Garden and it hardly made a peep out by the mix board, the working roadies were as loud. LOL

Live set-up at Red Hat Amphitheater has 80kW per each side of total power for most of the rock concerts.
Live set-up at Town Hall NYC had 22kW per each side during King Crimson performance
Cro-Bar night club NYC has 30kW per channel if all amps are on

my cousins husband still does much of NYC sound and light along with friends from Trueheart sound and they both tell of wayyy more potential running. its a big trick to phase every speaker to be additive but done well now with all the digital delay and inversion tricks so you can hit 110db a weighted with 1/2 the watts of the 802/ but its usually there on tap. and yea Crown is still major player but not the same co at all. remember the PS2H extra headroom amps for Kiss and alike they built.

Powered, likely class D, phased array or line array systems are pretty much the standard now. 1,000 or more watts per speaker (more for subs) so simply count 'em up. Note that the primary feature of the famous huge Dead system wasn't just midrange drivers, it was the fact that each musician was using their own discreet pile of PA speakers within the system, instead of the normal thing of everything mixed together.  This resulted in basically a complete, discreet system for each instrument...a logistic nightmare, but according to a friend who heard one of those shows, you could hear a clear Dead song from blocks away from the venue.