There are many different strength e-juice in the market from 0 mg to 36 mg.
My first choice was 26 mg (turned out a bit too strong for me), but what does it mean?
26 mg / 100 ml ? Or what?
And a different but not unrelated question:
How many ml e-juice equals 1 packet of cigarette?
26mg = 26mg/ml
It means there is is 26 milligrams of nicotine per 1 milliliter of liquid
This is 2.6% by weight
The common retail strengths of e-liquid are:
0, 6, 12, 18, 24, [30], 36, [45]
30 and 45 are less often seen
Most expert users will tell you that about 3ml of liquid is equal to a pack of cigarettes (20). If used in a carto, not all can be utilised as some stays in the filler, so about three and a half cartos or 3.5ml is about equal to 20 cigs (for ecig users past the initial stage).
The 'average smoker' apparently smokes about 15 cigs a day, and for them, about 3 cartos or 3ml vaped from cartos is about right.
Liquid goes further if dripped or run through a bottom feeder* into an atomizer, as none is held in filler. Tank systems work out about the same as bottom feeders.
* A boxmod with an integral tank, where the liquid is fed up through the base of the atty via the connector (ex: a Reo).