Nicotine Strength in e-liquid is measured in milligrams of nicotine per milliliters of e-liquid ie: 6mg/ml e-liquid contains 6mg of nicotine for every milliliter of e-liquid. However this is not the amount of nicotine you will absorb from taking a puff off your e-cigarette, or from vaping one milliliter of e-liquid . Not all the nicotine in the e-liquid is absorbed when vaping. On average e-cigarettes are less efficient at delivering nicotine than traditional cigarettes, but how often you vape, the device you are using and the strength of your e-liquid will all affect how much nicotine you are ultimately exposed to when vaping.
So which strength should you choose?
If you do not desire to use nicotine, or you do not already use products with nicotine (cigarettes cigars etc) choose 0mg/ml.
Though nicotine strength in e-liquid is not directly comparable to cigarettes, as a general guideline the more cigarettes you smoke the higher the nicotine strength you might prefer. Occasional and light smokers up to half a pack a day tend to prefer nicotine strengths of 3-6mg/ml, while regular smokers up to a pack a day or more usually prefer to start around 12-16mg/ml. Very heavy smokers used to harsher tasting or unfiltered cigarettes may prefer to start at 24mg/ml.
The device you are using will also affect how much nicotine is released when vaping. Sub-ohm devices will release more nicotine so many people feel they need to go down a nicotine strength or even two from what they would normally vape. Most commonly those using sub-ohm devices will choose a nicotine strength under 12mg/ml. Those using higher wattage batteries may also find they need to go down a nicotine strength.
We recommend ordering a couple different strengths your first time vaping until you get a feel for how much nicotine you prefer. If you order a strength that is too high for you can mix it with a lower strength or 0mg/ml to lower the amount of nicotine. For instance if you order 12mg/ml and find it is too strong you can mix it with an equal amount of 0mg/ml making the strength of the liquid 6mg/ml. Similarly you can mix a too weak e-liquid with a stronger liquid.