||Lets start with what 12mg or 24mg strengths mean for nicotine.
In short, it's the amount of nicotine in milligrams, for each millilitre of E-Liquid, expressed as mg/ml.
Some companies choose to represent this as a percent per solution, which is where you'll see 1.2% instead of 12mg/ml.
This means the same thing, just interpreted differently. The nicotine density listed for e-liquid is the number of milligrams of nicotine per milliliter in the E-Liquid.
That means a 10ml bottle of 24mg nicotine e-liquid would have 240mg of nicotine in it (24mg x 10ml). Likewise, a 30ml bottle of 24mg e-liquid would have 720mg of nicotine in it (24mg x 30ml).
No Nicotine: This level will work for you if you just want the feel of smoking a cigarette. If you are anything more than an extremely light (a few cigarettes a week) smoker, this won’t be enough. At least not in the beginning, but we’ll get to that later.
8mg or 0.8%: Considered the ultra-light level, 6mg can be effective if you are used to smoking ultra-light cigarettes such as Silk Cut or an ultra-light brand.
11mg or 1.1%: Here we start to get into the area where more smokers fall into. This would be considered a light level nicotine strength for most e-cigarette brands. If you smoke a light cigarette, especially if you smoke less than a pack a day, this could fit your needs well.
18mg or 1.8%: The majority of smokers will want to start with this level of liquid nicotine or higher. If you smoke a full flavored or regular cigarette and have up to a pack a day, you will want your e cigarette liquid to contain at least 18mg of liquid nicotine.
24mg or 2.4%: Now we’re talking! This nicotine strength level suites smokers used to "natural” cigarette brands like rolled tobacco. This could also be a good starting point if you smoke more than a pack a day of a full flavored cigarette.