Just curious: How big around are D size cups? C sizes?

I am a Christian, and I don't therefore really care about this but I am curious nevertheless. What is the difference in size exactly?In terms of inches? If you can tell me the inches of a DD too that would be great. I know DDD's are about as big as a guy's head.And I know B's are only about as big as a guy's hand. I'm mostly a foot guy, so I don't know much about this. Nor do I care. But still, I'm curious. And I feel inferior without knowing this.Please answer. Some jock guys today asked me about this, and subsequently called me an idiot for not knowing. I could have crushed them.Shown them the wrath of an Advanced Martial Arts practitioner. But.....no. I'm not going to elaborate. Just please answer my question. Thank you.