There are times in life when you know you're about to go hard. All the advice in the world about moderation tends to go out the window if, say, your hard-partying uncle is getting married. In Cabo San Lucas. During Spring Break. And you've just been dumped. At that point "know your limits," can become less important than "know the absolute limit," because you're on your way there.
And since alcohol is a pretty hard drug, the limit is what's known as a "fatal overdose," and it's not actually that hard to get there. "Zero-point-three percent to 0.4 percent, and you're in the danger zone. People have actually died at those blood levels," said George Koob, director of the National Institute on Alcohol Abuse and Alcoholism at the National Institutes of Health, when I asked him how much booze it would take to kill me.
But the amount of alcohol in your blood can't be measured reliably with the equipment that gets sold to consumers. Last year Seamus Bellamy of the Wirecutter tested all the consumer-grade breathalyzers, and concluded that the $180 BACtrack S80 was the most reliable, but it still wasn't worth an endorsement. So until a cheap, effective breathalyzer comes out, you have to keep yourself from dying the old-fashioned way: by stopping your binge drinking before it gets fatal.
It can be pretty complicated to figure out exactly where that line is. Everyone knows that some binges that heavy drinkers routinely engage in will leave others in a coma. But if you're planning on doing something stupid but seemingly possible, like downing an entire bottle of liquor, you should know that it's actually a suicide attempt for most people.
Hopefully, the guy in the video above puked right after he pushed stop on his recording. "A whole bottle of Scotch contains about 17 drinks," Koob told me. But 101-proof Wild Turkey has much more alcohol than Scotch. That means even if this guy's tolerance is high, "that's basically Russian roulette," Koob said.
But "Russian roulette" implies an amount of randomness, and there's actually a clear formula that can tell you how much is WAY too much, even for the large-bodied and booze-acclimated guy in the video above.
Figuring out the variables in that formula is tricky, however. You need to factor in your weight, your sex, what you've been drinking, and how long you've been at it. You can see a frame of a web app for it below—I used it to determine how many drinks it would take for me to get as shitfaced as the drunkest sorority girl of all time, Vodka Samm. The answer is 14 in one hour.
Samm became a folk hero of sorts last year when she blew a .341 while remaining not only alive, but still attempting to climb fences and interrupt sporting events. That is, it should be noted, four times the standard legal limit for driving.
That approximate BAC, .34, is a magic number of sorts: According to a lot of BAC charts it's the upper limit, on the border line between stupor and death, and it would take me—an average-sized American male—14 shots to get there.
The notorious 16-vodka breakfast enjoyed by Led Zeppelin drummer John Bonham on the day he died is actually very educational: His breakfast may have been a punishing dosage, but it was just a pre-game for a guy with a serious tolerance, according to rock historian Mick Wall—he kept working and drinking that entire day in 1980, eventually consuming a total of 40(!) drinks, only to lie down that night and choke to death on his own vomit.
"I can't give you a case history but there are individuals who put away that amount of alcohol per day," Koob told me. But assuming Bonham was hovering right around that .34 percent sweet spot all day, he was in constant danger.
According to Koob, size and a history of drinking are far from the only factors. "There's about one drink difference for females and males who are at the same weight," he told me. Then there's environment: "The cues, the color of the bar, the smells, all of those things become linked to the development of tolerance. A lot of people don't realize that, but it's actually psych 101."
While all this complexity adds up to a clearer picture of how alcohol affects you, it doesn't give you much of an answer to the question of how much you can drink before you die from it, and how to know when you're approaching that point without a law enforcement-quality breathalyzer.
There is a useful answer to be found by putting your drinking in perspective, however. Drinking starts out by causing the release of dopamine and other chemicals that make your brain feel nice. But that stops after a bit, and the experience starts to become grueling around the 0.08 blood-alcohol mark—at which point you're likely too drunk to drive.
"When you do so much of a drug, like alcohol, that releases all of those good things, they also trigger your stress axis," Koob said. "So then you end up with these chemicals in your brain that end up making you feel terrible." You know you're almost there when, like an addict, you've been drinking for a while and it's starting to suck, and you think drinking more will make it fun again. That's when you're liable to black out.
"That's not a place you wanna go because blackouts occur somewhere about 0.2," Dr. Koob told me. From there, he provided a roadmap to a useful personalized answer to the question of how many drinks would kill you: "If you can remember a timeline to follow back and see how much you drank to get to the blackout, that's a good way to [know] you've reached the limit."
So just count your drinks next time you get so hammered you black out, and make sure they're all standard-sized drinks (a.k.a. 14 grams of pure alcohol). That will tell you what your limit is.
If that method seems a bit risky, Koob also gave a simpler rule of thumb for what might kill an average-sized American: "Fifteen standard drinks in two hours."
And that's not a challenge. Drinking more than the four drinks it takes most people to reach 0.08 percent BAC isn't fun anyway. So stop there, and definitely don't blame me if you kill yourself.
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(Note: A previous version underestimated the amount of alcohol in Scotch.)