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How Long Does Alcohol Stay In Your Urine? Use Our Calculators

Dr. Drew Sutton MD

This article was reviewed and approved by Dr. Drew Sutton MD

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How long does alcohol stay in your urine can mean not going to jail or keeping your job. Drug and alcohol testing is a common occurrence in both the workplace or on the road. Even a small amount of alcohol can impair judgment, timing, and, therefore, the ability to operate a motor vehicle safely.

  • The legal limit for driving is .08% BAC or above.
  • Receiving a DWI conviction could mean going to prison for years.

Determining how blood alcohol content (BAC) depends entirely on the amount of alcohol consumed over the time spent drinking. Alcohol metabolizes at a rate between .012% to .015% of  their BAC per hour.

Blood Alcohol Concentration

BAC is the unit of measurement of how much alcohol is in someone’s body (percentage in the blood) at any given moment. BAC is still considered the primary standard for alcohol testing in some labs.

  • BAC is the answer to this equation; the total number of ethanol grams in 100 milliliters of blood.

Standard drink measurement

Generally speaking, beer is 4.5% – 5% alcohol for most tests. Wine uses a 5 oz glass, and hard liquor (shots & mixed drinks) uses 1.5 oz at 80 proof.

  • one beer (12 ounce)
  • one glass of wine (5 ounces)
  • 1.5 ounces of liquor (shot)

Calculator approximate BAC and Sober up time

Use the quick calculator to determine BAC (about) when a person stopped drinking. It will also calculate about how long it might take for the BAC to go down to zero.

How to use

  1. Using the standard drink list (above), count the total number of drinks, during a continuous drinking episode, and enter the number in the first line “Number of Drinks Consumed.”
  2. Determine how many hours were spent drinking, rounding up or down to the nearest half-hour. Enter that number in the “Number of hours Spent Drinking.

Quick BAC Calculator

Important: These results are rough calculations based on the average rate of human alcohol metabolization. It will be affected by these variables.

  • The legal limit for driving is .08

Gender

The reason gender is a crucial 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.

Also, women have a smaller amount of vasopressin or ADH than men.

Absorption rate factors involving gender indicates that a man weighing 140 pounds who consumes two drinks in one hour will have a lower blood alcohol level than a 140-pound woman who drinks the same amount of alcohol in the same amount of time. It is because men possess higher levels of the enzyme hydrogenase in their stomachs.

Weight

How much someone weighs is a factor because BAC is a function of grams of ethanol in 100 milliliters of blood. So, the more someone’s weight, the higher blood volume in their body.

Other Factors

Other aspects affecting BAC include age, tolerance, and physical fitness. These variabilities could produce a small fraction of error in the final answer. Here is how they might affect the outcome of our formulation.

Age

Younger people have a higher proportion of body water as a fraction of their total weight, and older people have less. So, a younger person may potentially have a lower rate than an older person.

Physical Fitness

Individuals who may be overweight may have a smaller proportion of their body weight as water. Lean people tend to have a more significant fraction of their body weight as water. Therefore, overweight people may have a lower BAC than our formula indicates.

Tolerance

A regular drinker will have a higher ability to metabolize alcohol than someone who does not drink as often.

EtG

Most alcohol testing labs now test the body’s chemical to process alcohol, namely EtG.

This test detects the presence of EtG in the urine. EtG is a direct metabolite the body uses to process alcohol. Its urine presence detects alcohol consumption in the past 80 hours (approximately).

The time factor is dependent on many variables not in this calculation. Therefore, it is merely a rough estimate and not a guarantee of passing a test.

ETG Calculator

Quick EtG Calculator

Select the day the person stopped drinking

Select the time the person stopped drinking

This person is at high risk to fail an EtG test until at least:

Metabolization

The liver metabolizes most alcohol, with the remainder excreting through urine, sweat, and breath. The human body metabolizes alcohol as soon as the person begins to drink. So, in theory, if you drank at a rate of approximately .015% BAC per hour, your BAC would stay very low.

Once alcohol reaches the stomach, hydrogenase starts breaking down alcohol molecules.

Additionally, alcohol inhibits the 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.

  • When five percent of absorbed alcohol reaches the kidneys, the body actively excretes alcohol through urination.
  • Metabolism varies and runs primarily on liver metabolism. Still, it is also related to age, gender, weight, presence of food in the stomach, number of drinks per hour, percentage of alcohol in the glass, and if the person takes other drugs or medicines.