It all depends on what you mean. If you mean to stay high it depends on the potency of the product and how deeply one inhales. On average a bowl or two of average marijuana will last from 1-3 hours, sometimes more or less depending on body weight and individual susceptibility. One hit would probably last around 45min-1hr 30min but you may not even notice it at all.
If you mean to get it out of your system for testing it (the THC) stays in urine (if you don't often smoke marijuana) for generally a week or less, sometimes upto a month but this is rare for a small amount with infrequent usage. It can stay detectable in hair upto 6 months (unless cut) but most workplaces and otherwise do urine tests, hair tests aren't as common. THC stays in your bloodstream only for a few hours. As for tests, usually the common ones are accurate to (sometimes) 90 days if you commonly smoke.
couple days that's it, 2 and your good
It takes a long time, weeks.
a month
Less than 15 days.
Smoke sum
about a week.
Answer2-3 days
weed will be in your system immediately and it stays in your system the longest because it is absorbed into your fatty tissues.Up to 30 days you should consider yourself dirty for a urine test.
it will take about 31 days to get good weed out of your system naturally for a person over 200lbs
3
0 days
2 weeks
one week