Depending on your set-up, 2-4 people.
On one site, I'd say 6 is the max (2 in the car, 4 in a tent) ... I've never camped with just one site though, so that might be on the high side.
I say 4 comfortably. Take your tent down each morning for more space during the day.
8/7 Tame Impala @ Hollywood Forever
8/20 Metz @ Echo
8/21 Modest Mouse @ Hollywood Forever
8/22-8/23 FYF Fest @ Exposition Park
8/26 Savages @ Roxy