A 24 oz beer at standard strength (5% ABV) equals about two standard drinks, and your body will fully metabolize it in roughly 2 to 3 hours. But “in your system” can mean different things depending on whether you’re thinking about feeling sober, passing a breathalyzer, or clearing a urine test. Each of those timelines is different.
How Many Drinks Are in a 24 Oz Beer
One standard drink in the U.S. contains 14 grams of pure alcohol, which is the amount in a regular 12 oz beer at 5% ABV. A 24 oz beer at that same strength is two standard drinks. That math changes quickly with higher-alcohol beers: a 24 oz craft beer at 7% ABV works out to about 2.8 standard drinks, and a 9% ABV double IPA in a 24 oz can is closer to 3.6. Since your body processes alcohol by the drink, not by the container, the ABV matters as much as the size.
How Fast Your Body Clears Alcohol
The average person metabolizes alcohol at a rate that lowers blood alcohol concentration (BAC) by about 0.015 to 0.020 per hour. That’s roughly equivalent to one standard drink per hour, though it varies from person to person. For a 24 oz regular beer (two standard drinks), most people will have a BAC of zero within 2 to 3 hours after finishing the beer.
Your starting BAC determines the timeline. A person weighing around 100 pounds who drinks two standard drinks will reach an estimated BAC of about 0.075, just under the legal driving limit. Someone at 150 or 180 pounds will peak considerably lower. From whatever your peak BAC is, subtract about 0.015 to 0.020 for each hour that passes. When you reach zero, the alcohol is fully metabolized.
Several factors speed up or slow down this process:
- Body size and composition. More muscle mass and body water means alcohol is diluted across a larger volume, resulting in a lower peak BAC. More body fat means a higher concentration in the blood.
- Biological sex. Women generally absorb more alcohol and take longer to process it than men of the same weight, largely because of differences in body water content, fat distribution, and hormones.
- Food in your stomach. Drinking on a full stomach slows absorption, which lowers your peak BAC and can make the overall clearance feel faster.
- Liver health and genetics. Some people produce more of the enzymes that break down alcohol. Liver conditions slow processing significantly.
Breathalyzer Detection
A breathalyzer measures alcohol vapor in your breath, and for a 24 oz regular beer, it will typically read zero within 2 to 4 hours for most people. However, breathalyzers can detect trace amounts of alcohol on the breath for up to 12 hours in some individuals, and in rare cases up to 24 hours. The more precise answer depends on your peak BAC: divide it by 0.015, and that’s roughly how many hours until you’d blow 0.000. For two standard drinks in a 160-pound man, that’s often under 3 hours.
Urine and EtG Testing
Standard urine tests that check for alcohol itself have a detection window similar to blood and breath, usually clearing within a few hours of your last drink. But many employers and courts use a more sensitive test that looks for ethyl glucuronide (EtG), a byproduct your body creates when it breaks down alcohol. EtG can be detected in urine for up to 48 hours after a few drinks. For a single 24 oz beer, you’re looking at a realistic detection window of roughly 24 to 48 hours on an EtG test, depending on sensitivity thresholds and your individual metabolism.
This is the test that catches people off guard. You can feel completely sober, blow clean on a breathalyzer, and still test positive on an EtG screen the next day.
Hair Follicle Testing
Hair tests work on a completely different timeline. Alcohol metabolites get incorporated into the hair shaft as it grows, and a standard hair follicle test can detect alcohol use from 1 to 6 months in the past. The typical look-back window is about 3 months, based on the standard 1.5-inch hair sample collected. A single 24 oz beer is less likely to trigger a positive result on a hair test than repeated heavy drinking, since these tests are generally designed to identify patterns of use rather than isolated occasions.
When You’ll Actually Feel Sober
Feeling sober and being alcohol-free are not the same thing. Most people stop feeling the effects of two standard drinks within 1 to 2 hours, but measurable alcohol remains in the blood beyond that point. The reverse can also happen: you might feel fine while your BAC is still above the legal limit, especially if you drink regularly and have developed some tolerance. Tolerance changes your subjective experience but does not change how fast your liver processes alcohol. Your metabolism rate stays roughly the same regardless of how often you drink.
For a 24 oz beer at 5% ABV, the practical answer is that alcohol leaves your bloodstream in about 2 to 3 hours, clears a breathalyzer in a similar window, stays detectable on an EtG urine test for up to 48 hours, and can show up on a hair test for months. If the beer is a higher ABV craft beer, add roughly an hour of metabolism time for each additional standard drink equivalent.