i've been smoking for almost 3 months i started at age 12 but i've had my 13th-day since so i'd say 12 or 13 at the earliest anything below that is way 2 young i think like that 1 dude who started ciggarettes at 8 yrs old im like wtf ur lungs r gonna be fucked by the time u graduate but hey its ur life do w/e the fuck u want