Trying to determine how long alcohol stays in your urine system is a complicated mathematical formula. It is primarily based on multiple variables.

In the human body, alcohol is metabolized at a rate between .012% to .015% of the blood alcohol concentration (BAC) per hour.

A standard drink is considered one 12 oz. beer, one 5 oz. glass of wine or one 1.5 ounces of hard liquor. If someone was over the legal limit with a BAC of .09%, it would take approximately 2 hours for the average person to metabolize the alcohol in their system.

Blood Alcohol Concentration – BAC

When about five percent of absorbed alcohol reaches the kidneys, the body begins actively excreting alcohol through urination.

Additionally, alcohol inhibits production of vasopressin, a hormone that helps conserve body fluids. Without vasopressin to prevent fluid loss, urination increases and the body usually begins excreting alcohol within 20 to 25 minutes of being consumed.

However, determining how long alcohol remains detectable in your urine really depends on how much you drink along with the other factors mentioned above.

Primary Factors in BAC

Essentially a person’s blood alcohol concentration is based on the amount of alcohol consumed in a specific period of time. Here are some of the factors which alter the length of time it takes to “sober up”.

1. Gender Type

The reason gender is a key factor is men have a higher percentage (.58) of water weight than women (.49) by almost 10%. That means a woman’s BAC will be higher since BAC is based on converting water into the amount of blood in their body.

2. Body Weight

How much someone weighs is a primary factor because blood alcohol content (BAC) is a function of “grams of ethanol in 100 milliliters of blood”. So, the more someone weighs the higher volume of blood there is in their body.

3. How Much Alcohol Was Consumed

The more alcohol someone drinks, the more alcohol your body needs to metabolize. Generally speaking, for most BAC tests, beer is figured as 4.5% – 5% alcohol, wine is figured using a 5 oz glass and hard liquor (shots & mixed drinks) are figured using 1.5 oz. at 80 proof.

4. Time Period of Drinking

The human body starts to metabolize alcohol as soon as the person starts to drink. In theory, if you drank at a rate of approximately .015% BAC per hour, your BAC would stay at zero.

How The Body Metabolizes Alcohol

There are many factors which effect the blood alcohol concentration (BAC) in someone’s body who has been drinking. BAC is the answer to this equation; total number of grams of ethanol in 100 milliliters of blood.

Once alcohol reaches the stomach, hydrogenase starts breaking down alcohol molecules, which facilitates metabolization by the body’s tissue and organs, specifically the liver.

In addition, women present even higher blood alcohol levels compared to men just before menstruation since they also have lower percentages of water and higher percentages of alcohol-retaining fat cells.

Absorption rate factors involving gender indicate that a man weighing 140 pounds who consumes two drinks in one hour will have a lower blood alcohol level than a 140-pound women who drinks the same amount of alcohol in the same amount of time.

This phenomenon can be explained by the fact that men possess higher levels of the enzyme hydrogenase. Also, men have a higher amount of water in their bodies than women.

Ethyl Glucuronide – EtG

An EtG type of test detects the presence of ethyl glucuronide in the urine. EtG is a direct metabolite the body uses to process alcohol. Its presence in urine may be used to detect alcohol consumption in the past 80 hours.

With an EtG, a positive urine test is still possible 3 to 4 days even after low to moderate drinking.

The answer most people are looking for is “how long after I stopped drinking will I be able to pass a drug screening test.” The answer actually depends on whether the test is a standard test or an EtG. More and more testing clinics run an EtG type test, but not all.

Quick EtG Calculator Select the day the person stopped drinking Day Monday Tuesday Wednesday Thursday Friday Saturday Sunday Select the time the person stopped drinking Time Calculate This person is at high risk to fail an EtG test until at least:

The Science Behind EtG

Some labs now use a testing method known as “EtG” for discovering how long ago someone metabolized alcohol.

Ethyl Glucuronide is a biomarker that determines whether the body has metabolized any alcohol recently. If a method known as “EtG” is used to test for the presence of a related chemical, ethyl glucuronide in the urine, the results can determine if alcohol has been ingested within approximately the past 80 to 90 hours.

The “EtG” Urine Alcohol Test detects ethyl glucuronide in the urine, which confirms alcohol ingestion as long as 3 to 4 days prior, or about 80 to 90 hours after the liver metabolizes alcohol.

The EtG test has become known as the “80 hour test” for detecting any amount of consumed ethyl alcohol recently. EtG has emerged as the test of choice for alcohol due to the accuracy of the technology and is now routinely available.

Its presence in urine may be used to detect recent alcohol consumption, even after ethanol is no longer measurable using other methods. The presence of it in urine is a definitive indicator that alcohol was ingested recently.