Answer to how long does weed stay in your system cannot be answered explicitly. Why? Becouse the answer depends alot on how big you are, how fast you digests, how often you smoke and many other factors.
Usually it takes from 3 to 30 days to get all weed out of the system, but this can take much longer as well. Traces of weed in your urine can be detected up to 3-4 months after you’ve smoked it. Not to mention the hair, where it can be traced years after you’ve stopped smoking it.
Now even though the time frame is very big in this answer, we can give you an estimate. If you are a regular smoker, traces of weed will stay in your body for around 40-60 days. But as I said, this can go up and down for a month or even two. And if you’ve smoked it only once, then it is very likely that your body will put it out within 3 weeks.
Remember, if you run into any problems, seek doctors right away. Do not wait for it to get out of the system. Go to the doctors and they will get it out faster!