Usually 1-2 per day. During my lunch break I go into a conference room or empty office, and have a small cigar. Unfortunately, only employees with closed offices can smok cigars at their desk. Since I work in a cubicle, I cannot have a cigar.
On Thursdays, Fridays, and Saturdays I can smoke 3-4 cigars.
There are people in my company who smoke 6-10 cigars a day.