Really does depend.I dont think because you are a lightweight u will smoke less.I weigh 65kg my brother weighs between 100-110kg thats a big man.He only smokes weekends but i smoke every day.I know it dont count really but i can smoke so much more than he can.If i dont smoke for a week i will have one cone and im feeling fine and stoned too.It really does depend on how often and how much u smoke.Like tag said just experiment.Have one and wait a little while because it might be a creeper.If you feel ok in maybe 10 15 mins pull another or 2.