I am going on memory here...(which is your first hint to possibly ignore this information)
Carnival Fantasy Class 185sq ft
Carnival Conquest Class 220 sq ft
I do know that we have slept 4 to a cabin for years without a problem.
However, the inside that we had on the Miracle was not big enough for 3 people (IMHO). Just a heads up. We had no problem with the Balcony on the Spirit or the 5A on the Pride.
Dave, I keep that site up 24/7. Never have to look through the borchures with a magnifying glass to find a cabin location and description that way. When they take it down for maint I'm frustrated and ineffecient until they get it back up.
I'm told many agents use it as I do. I'm also told many traditional use another site to quickly find available cruises by multiple lines in a hurry for clients .