Rooms aren't equal, so rent shouldn't be either. Weigh size, a private bath, the closet, light and parking, handle a couple sharing a room, or have everyone bid on the rooms and get a split where nobody would rather swap.
The "shared space" slice (kitchen, living room, hallway) is split evenly per person. The rest is split by how good each room is. Utilities always split per person.
Each is a bonus on top of the room's square footage. Size counts in full unless you turn down "Size matters".
Each party (a person, or a couple sharing a room) writes what they'd pay for each room, so their row adds up to the rent. Be honest: the split rewards it.
Check grid: what each party would "save" vs their bid in every room at these prices. Green is their room; red would mean they'd rather swap.