For most people, two to three drinks in an hour will produce noticeable intoxication, while four to five drinks in two hours will push blood alcohol concentration (BAC) to 0.08%, the legal limit for driving in every U.S. state. But the real answer depends heavily on your body weight, biological sex, whether you’ve eaten, and how fast you’re drinking.
What Counts as One Drink
Before anything else, it helps to know what “one drink” actually means. In the United States, a standard drink contains about 14 grams of pure alcohol. That works out to a 12-ounce beer at 5% alcohol, a 5-ounce glass of wine at 12%, or a 1.5-ounce shot of liquor at 40%. These all deliver roughly the same amount of alcohol to your bloodstream, even though the volumes look very different.
The catch is that real-world drinks rarely match these neat definitions. A pint glass holds 16 ounces, not 12. Many craft beers run 7% to 9% alcohol. A generous restaurant pour of wine can easily hit 7 or 8 ounces. A strong cocktail might contain two or three shots. So when you count your drinks, the number on your mental tally may be lower than what your body is actually processing.
How Your Body Turns Alcohol Into a BAC Number
Your BAC is determined by a straightforward relationship: how much alcohol you consume versus how much water is in your body to dilute it, minus however much your liver has already broken down. A larger person has more body water to absorb alcohol, so the same number of drinks produces a lower BAC in someone who weighs 200 pounds than in someone who weighs 130.
Your liver clears alcohol at a relatively fixed pace, lowering your BAC by roughly 0.01% to 0.02% per hour. That means your body eliminates about one standard drink per hour. Drink faster than that rate and your BAC climbs. Drink slower and it stays low or drops.
Why the Same Number of Drinks Hits People Differently
Biological sex creates one of the biggest gaps. Men have highly active forms of the enzyme that breaks down alcohol in both the stomach and liver. That stomach enzyme alone can reduce how much alcohol enters the bloodstream by about 30%. Women produce almost none of this enzyme in the stomach, and the version in their liver works less efficiently. On top of that, women typically carry a higher proportion of body fat and less body water than men of the same weight, which means alcohol is less diluted. The practical result: a 150-pound woman will reach a higher BAC than a 150-pound man after the same number of drinks, often significantly so.
Body weight matters independent of sex. A 120-pound person might hit a BAC of 0.08% after just two or three drinks in an hour, while someone at 220 pounds might need five or six drinks in the same window to reach the same level. Age, genetics, liver health, and how frequently you drink also play a role. Regular heavy drinkers develop tolerance, meaning they may feel less impaired at a given BAC, but their actual impairment and health risk remain.
What Each BAC Level Feels Like
Intoxication isn’t a single switch that flips. It’s a gradient, and each stage brings distinct changes:
- 0.02% (roughly one drink): Slight relaxation, mild warmth, a subtle shift in mood. You may already have some decline in your ability to track moving objects or divide your attention between two tasks.
- 0.05% (two to three drinks): Lowered alertness, reduced inhibitions, exaggerated behavior. Small-muscle control starts slipping, including the ability to focus your eyes. Most people feel noticeably “buzzed” here.
- 0.08% (four to five drinks in two hours): Poor coordination affecting balance, speech, vision, and reaction time. Judgment, self-control, reasoning, and short-term memory are all impaired. This is the legal driving limit and the threshold most people would describe as “drunk.”
- 0.10%: Clearly slurred speech, slowed thinking, obvious loss of coordination and reaction time.
- 0.15%: Major loss of balance and muscle control. Vomiting is common unless tolerance is high.
These numbers come from the National Highway Traffic Safety Administration and represent averages. Some people feel significant effects earlier, especially if they drink infrequently or have a smaller frame.
Food Makes a Bigger Difference Than Most People Realize
Drinking on an empty stomach is one of the fastest ways to get drunk. Alcohol absorbs much more rapidly when your stomach is empty because there’s nothing to slow it down on its way to the small intestine, where most absorption happens. A solid meal before drinking delays gastric emptying, which slows alcohol absorption substantially and also increases the rate at which your body eliminates it. The result is a lower, later peak BAC.
This isn’t a small effect. Eating a full meal before drinking can cut your peak BAC by a meaningful margin compared to drinking the same amount on an empty stomach. Liquid meals help too, but solid food works better. If you’re wondering why two beers hit you hard one night and barely registered another, what you ate (or didn’t eat) beforehand is often the explanation.
Binge Drinking Thresholds
The NIAAA defines binge drinking as the amount that brings your BAC to 0.08% or higher. For a typical adult, that corresponds to five or more drinks for men, or four or more drinks for women, in about two hours. For younger people, the threshold is even lower: as few as three drinks in the same window, depending on age and size.
High-intensity drinking, a pattern that carries sharply elevated risk, is defined as double those numbers: ten or more drinks for men, or eight or more for women, on a single occasion. These aren’t arbitrary cutoffs. They reflect the BAC levels where the risk of accidents, injuries, and acute health consequences rises steeply.
When Alcohol Becomes Dangerous
The gap between “drunk” and “in danger” is narrower than many people assume. At a BAC of 0.30% to 0.40%, alcohol poisoning becomes likely, with loss of consciousness a real possibility. Above 0.40%, the risk of coma and death from respiratory arrest (your body simply stops breathing) is significant. These levels can be reached surprisingly fast during drinking games, with high-proof spirits, or when someone drinks large amounts in a short window.
Your body can only eliminate about one drink per hour, and that rate doesn’t speed up no matter how much coffee, water, or food you consume after the fact. If someone passes out and cannot be woken, or is breathing slowly or irregularly, that’s a medical emergency.
Putting It All Together
As a rough guide for a person of average weight drinking standard-sized drinks over about two hours: two to three drinks will produce a noticeable buzz, four to five will bring most people to or past the legal limit, and anything beyond that enters territory where coordination, judgment, and safety deteriorate quickly. But your individual number depends on your weight, sex, what you’ve eaten, how fast you’re drinking, and your personal biology. A 130-pound woman drinking wine on an empty stomach could feel significantly impaired after two glasses, while a 220-pound man who just ate dinner might handle three or four beers before reaching the same point.
The one constant is the math: your liver processes roughly one drink per hour, and everything beyond that accumulates. Spacing your drinks, eating beforehand, and knowing that “one drink” at a bar is often more than one standard drink are the most practical tools for staying on the side of the line you intend to be on.