Geez, hard to say since I use a little of this & a little of that throughout the day. When I first started I used 10 ml bottles (was getting ripped), and one would last 5 days (sometimes 4)....so, 2 to 2 1/2 ml. a day. If you work the math, 1 ml. approximates 1 pack of (full flavor) cigarettes, using about 18-20 mg. strength. That all works real nice, except we really don't know how much of that nicotine we are actually getting. Some say it could be as low as 50% or even less, others more like 60% or more. So, 3 ml. is probably about equal to 2 packs a day.