hey i was wondering if i could give you my height and you can try your scaling method to see what size my helmet should be. i just wanted to compare what you got with what i got. my height is 71 inches tall, in cm its 180.34, and thats without the add on of a couple cm. its for an iron man helmet. for trying your scale method i got that the helmet should be 30.1cm or 301mm tall. please help and thank you for your time.