Established height?

Apologies if (almost certain) this has been asked before, wasn't able to find anything with the search option.
I'm working under the assumption that Optimus Prime from the G1 cartoon/movie, and the Dreamwave/IDW universes are meant to be around the same height? (give or take a couple of feet/inches) Has Optimus' height (and width) ever been established?
The main reason I'd like to know is, I've asked the multi-talented Fourth Heir to do yet another commission for me (3rd one now
, this time featuring three of my characters (Airlift, Bandit/Bounder and my main City Of Heroes character Ultrakid II) as well as Superman, Captain America, and my favourite Autobot, G1 Optimus.
As Fourth Heir pointed out to me, if he featured Optimus in robot mode, then UKII and Bandit would look really small, so I suggested he have Optimus bending down on one knee.
If Optimus' height and width haven't been canonized, then a rough estimation will be great.
Many thanks
I'm working under the assumption that Optimus Prime from the G1 cartoon/movie, and the Dreamwave/IDW universes are meant to be around the same height? (give or take a couple of feet/inches) Has Optimus' height (and width) ever been established?
The main reason I'd like to know is, I've asked the multi-talented Fourth Heir to do yet another commission for me (3rd one now

As Fourth Heir pointed out to me, if he featured Optimus in robot mode, then UKII and Bandit would look really small, so I suggested he have Optimus bending down on one knee.
If Optimus' height and width haven't been canonized, then a rough estimation will be great.
Many thanks
