We know that cannabis is the most used drug in the entire world. But the actual numbers are still pretty surprising.
The United Nations released a new report about drug use around the world. Once again, marijuana reigned supreme as the most used drug in the world with 192 million users, which is actually an increase of 10 million users from the same report released last year. The report also said marijuana is the most commonly used drug by adolescents, although that's not really surprising since it's the most used drug by all ages by such a wide margin.
To put that 192 million users in perspective, the second most commonly used drug in the world is opioids with only 34 million users. And if those 192 million cannabis users started their own country, that country would have a greater population than all but six nations in the world.
It should be mentioned, however, that these statistics are based on data collected in 2016. The true number of cannabis users in the world right now could be far greater, especially when you consider California (which would be around the 38th most populous country in the world if it hypothetically broke off from the United States) legalized the drug recreationally, and several states in America as well as the country of Uruguay have legalized the drug and increased sales over the past two years. So the 192 million users is frankly an underestimation of the number of actual users today.
(The UN report from last year acknowledged that their data could be an underestimation and that it's possible the actual number was closer to 238 million. This year's report did not contain similar information.)
So in short we should say there's AT LEAST 192 million marijuana users around the world today.