In a study of 11,426 teens, 25 percent said they had already smoked marijuana. About 13 percent said they had smoked marijuana during the previous month, and 6 percent had smoked more than four times in the past month.

Many parents find these statistics alarming. Our marijuana use calculator can help you assess your teen's likelihood of using marijuana. The answer can help you educate your teen about the consequences of substance abuse.

Please select the appropriate response to the following question:

Question 1 of 11: Select your teen's grade-level in school (if your teen is not currently enrolled, please pick the grade your teen would be in if he were in school): 7-8 9-12

The information on this Web site is provided as a public service by the University of Maryland Medical System, a regional health care delivery system that includes an academic medical center (the University of Maryland Medical Center in downtown Baltimore) as well as five community and specialty hospitals and outpatient sites throughout Baltimore and central Maryland. This information is not intended to be a substitute for individual medical advice in diagnosing or treating a health problem. Please consult with your health care provider about your health care concerns. If you would like to make an appointment with a University of Maryland physician, please call 1-800-492-5538.