Enough to go to jail for a VERY long time. But at least enough to be able to smoke a few bowls an hour for many many months. But seriously, way too vague to answer accurately. If you have a plant that will yield an average of 300-350gr per plant (wet), you can figure on 1 to 1 1/2 oz per plant dried & cured. But still very vague: how tall will you let them grow, how much topping will you do, type of nutes and frequency of use, changing light spectrum from veg stage to flower stage, training and tying.....etc. etc. etc. Good luck