How Common is Your Birthday? This Infographic Will Show You

(Image credit: Ashley Poskin) The Birthday Problem paradox suggests that if you put 23 people into a room, there's a 50 percent chance that two of them share the same birthday (and that probability jumps to 99 percent chance with just 60 people). The math is based on the assumption that every date out of the 365 days a year is equally likely for a birthday, but apparently that theory is way off.