Don't compare them - cigs vs ejuices - you didnt absorb all the nic in a cig and its the same for ejuice, minues the extra 4 thousand or so extra chemicals. They don't taste alike or affect you exactly the same way.
There is only ONE way to work out 'your' nic requirement from juices and thats to try a few different strengths. Every person is different, even those who smoked the same brand as you and the same amount as you did.
Its better to start too high than too low (you can cut high nic juice with same flavor lower one so its not a money sink excercise) and most pack a day smokers usually try a 24mg first. SOme stay there, others drop lower. Headaches or 'the runs' are a good inidcation the nic level was too high, wanting a smoke is usaully an indication its too low.
You will also need time to adjust to vaping so give yourself that time, and if you can't quit right away (or don't wish to, whatever you want) then its fine. Many people buy a PV to reduce the number of cigs they use, and quit by accident anyway; just don't compare yourself to other people's progress. You probably know this anyways but this is the new members thread and other people might find the info useful

As for how much you'd need to vape - thats another personal thing - 'when you feel satisfied' is the best answer really. I vape 12mg and thats good for ME, but because i love flavors I tend to chain vape late at nights and 12mg MOSTLY doesnt give me any issues for that. 0mg nic i good for chaining on as well - my habit seems to be way more hand/mouth than nic cravings
