Based on this image, the fact that Optimus Prime (who is in his hand at the moment) is usually recorded at around 32 ft tall, and doing some generalized math works, I have estimated that Metroplex stands at aprox. 3548 ft tall. That is more than 10 times the size of the largest incarnation of Godzilla. (328 ft)

Transformers: Honest Titles

Transformers 1: Optimus Prime, Dealing With Everyone’s Shit

Transformers 2: Optimus Prime: Brought Back to Life, To Deal With More Shit

Transformers 3: Optimus Prime, Gettin’ Real Tired of Everyone’s Shit

Transformers 4: Optimus Prime, 100% Done With Everyone’s Shit