It varies for me. If I really like the flavor, I go through it faster. Also, I vape less at work with higher nic (24) because of having to take breaks or stealth vape, than at home when I can chain vape. (12/18 nic). Oddly enough, I've found that I go through 50/50 a lot faster than 80/20, evan at the same nic level. Total averages 3 to 4 ml a day, give or take.