Here’s the simple formula: If you or your partner is tall (over 6’2” or so), get the California King. Your feet will thank you, and you won’t have to sleep diagonally like a weirdo.
If you’re average height but want maximum spread-out room for you, a partner, two dogs, and a stack of magazines, go for the regular King. It’s the “let’s all be comfortable, but not speak to each other” bed.
At the end of the day, both are gigantic upgrades from your college twin. Just remember: sheet shopping becomes a nightmare. Those fitted sheets are the love language of frustration. But hey, that’s a problem for future you. For now, go stretch your legs—or just sprawl like a starfish. You’ve earned it.
