>>5794532fair enough, here we go
Optimus is just shy of the same height as the last digit in Metroplex's pointer finger.
Optimus is about 40 pixels in height and the finger is about 45.
It takes 19 of those pointer fingers to make a whole Metroplex from top of head to roughly his feet (hard to judge exactly since his feet are splayed here.
So that's 19 Optimus at least so far, plus accounting for 19 extra 5 pixel differences, we 95 extra pixels or about 2 extra Optimus
So that puts us at Metroplex being 21 Optimus high rather than 30, so if Optimus is still 18 feet, Metroplex would be 378 feet or 115 meters