Also, 1 ml of water is 1 gram, and that's where the confusion comes from. That doesn't mean that your
juice is 1 gram per ml., because it has a higher weight/density than water. It's in the ballpark, though.
A lot of vapers, especially new ones, seem fixated on calculating the exact amount of nicotine they consume in one day, one vape, one hour, etc. (I'm not saying that is the reason for your question, I'm just expounding on the subject). It seems like an odd compulsion to me, because I don't know of
anyone who did that when they smoked.
I think the newness of vaping makes some people uneasily suspicious that they might be consuming dangerous or alarming amounts of nicotine. The thing is, you know when you've had "enough" nicotine by the way you feel, exactly the same as when you smoked.
Besides, it's almost impossible to do more than guess at the answer. You don't absorb all of the nicotine that you vape. People all vape differently, so there isn't even a reasonable way to estimate. The only way would be to do a blood analysis several times per day, throughout several days, and extrapolate from the results. Again, a guess.
The exact same thing is true of smoking cigarettes. It doesn't make any difference what "mg" # is on the pack, that tells you almost nothing about your nicotine intake.