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EtG Calculator

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Pharmacokinetic research basis·Updated Mar 2026·Free, no signup

EtG Detection Calculator

Based on pharmacokinetic research

How It Works

Use the Calculator

1

Enter Your Drinking Details

Input how many standard drinks you consumed and over how many hours. A standard drink is 14g of pure alcohol — equivalent to one 12oz regular beer (5%), one 5oz glass of wine (12%), or 1.5oz of 80-proof spirits.

2

Enter Your Body Weight

Body weight affects EtG concentration in urine. Larger body mass generally means a lower peak EtG concentration per drink, which can slightly shorten the detection window. Enter your current weight in pounds.

3

Select Your Test Cutoff

Most standard workplace and clinical EtG urine tests use a 500 ng/mL cutoff. Strict sobriety monitoring programs (such as probation, drug courts, or alcohol treatment programs) often use 100 ng/mL, which extends the detection window significantly.

4

Review Your Detection Window

The result shows your estimated detection window in hours and an approximate "clear by" time. Use this as a planning estimate — individual metabolism varies, and this should not be used to defeat a legitimate sobriety monitoring program.

Our Approach

How We Calculate

EtG (Ethyl Glucuronide) is a direct, non-volatile metabolite of ethanol produced by hepatic glucuronidation. Because it is unaffected by volatilization or fermentation artifacts, EtG serves as a sensitive and specific biomarker of alcohol consumption. This calculator estimates the urine EtG detection window using a pharmacokinetic model derived from peer-reviewed human studies.

Peak urine EtG concentration is estimated using empirical data from Høiseth G et al. (Forensic Science International, 2007), which documented peak concentrations of approximately 350–450 ng/mL per standard drink at a 70kg reference body weight. The model applies a weight-normalized adjustment and uses first-order elimination kinetics with an EtG urine half-life of 3.0 hours — consistent with the 2.5–3.5 hour range reported across multiple studies. The total detection window is computed as the time required for the peak concentration to fall below the selected cutoff threshold (100 or 500 ng/mL), per the formula: t = (ln[Peak/Cutoff] ÷ ln[2]) × half-life. Hydration adjustments reflect published findings from Wurst FM et al. (Addiction, 2003) documenting significant concentration effects from fluid intake on EtG urine levels. All results are estimates. Individual variation in glucuronidation enzyme activity, liver function, kidney function, and urine output can materially affect actual detection times.

Sources & References

  • Høiseth G, Bernard JP, Karinen R, et al. "A pharmacokinetic study of ethyl glucuronide in blood and urine: Applications to forensic toxicology." Forensic Science International. 2007;172(2-3):119-124.
  • Wurst FM, Skipper GE, Weinmann W. "Ethyl glucuronide — the direct ethanol metabolite on the threshold from science to routine use." Addiction. 2003;98(s2):51-61.
  • Jatlow P, O'Malley SS. "Clinical (nonforensic) application of ethyl glucuronide measurement: Are we ready?" Alcoholism: Clinical and Experimental Research. 2010;34(6):968-975.
  • SAMHSA — "Mandatory Guidelines for Federal Workplace Drug Testing Programs" (2017 revision)
  • Society of Hair Testing (SoHT) — "Consensus of the Society of Hair Testing on alcohol markers in hair." Forensic Science International. 2020.

Data last verified:

FAQ

EtG Detection — Common Questions

EtG (Ethyl Glucuronide) is a minor metabolite of ethanol produced when your liver processes alcohol via glucuronidation. Unlike ethanol itself, which is detectable in urine only for 6–12 hours, EtG persists in urine for 24–80 hours depending on how much was consumed. This makes EtG a much more sensitive biomarker for recent alcohol use. It is widely used in sobriety monitoring programs (probation, drug courts, alcohol treatment programs), pre-employment and workplace testing, and clinical settings where recent alcohol use needs to be detected beyond the ethanol detection window.
EtG detection windows in urine depend heavily on the amount consumed and the test cutoff level used. For light drinking (1–2 standard drinks), EtG is typically undetectable at the 500 ng/mL cutoff within 24 hours. Moderate drinking (3–5 drinks) extends detection to 24–48 hours. Heavy drinking (6+ drinks) can result in positive results at 48–72 hours, and very heavy drinking (10+ drinks) may produce detectable EtG at 72–80 hours at the 100 ng/mL cutoff. These are averages — individual metabolism, hydration, kidney function, and liver enzyme activity all affect actual results.
The cutoff level determines how sensitive the test is. At 500 ng/mL (the standard cutoff used in most workplace and clinical EtG tests), the detection window is shorter — the test only triggers positive when EtG concentration is relatively high. At 100 ng/mL (used in strict sobriety programs like probation, drug courts, and some treatment programs), even trace amounts of EtG trigger a positive result, extending the detection window considerably. If you are subject to a 100 ng/mL test, your detection window may be 30–50% longer than for a standard 500 ng/mL test. Always confirm the cutoff level being used in your program.
This is a legitimate concern in sobriety monitoring contexts. Some studies have found that consuming products containing trace ethanol — such as certain mouthwashes (Listerine contains alcohol), hand sanitizers (if absorbed or ingested), fermented foods, and some medications — can produce low-level positive EtG results, typically in the 100–300 ng/mL range. At the 500 ng/mL cutoff, most incidental exposures do not produce false positives. At 100 ng/mL, incidental exposure from alcohol-containing products is a documented concern. Programs using 100 ng/mL cutoffs typically have protocols to evaluate reported incidental exposures.
Hydration does affect EtG urine concentration — drinking more water dilutes your urine, which can lower the EtG concentration below the detection threshold sooner. However, this does not eliminate EtG from your body; it only affects concentration in any given urine sample. Some testing programs are aware of this and may flag specimens with very low creatinine levels (indicating excessive dilution) as invalid or suspicious. Drinking water is generally healthy and may modestly accelerate clearing the detection threshold, but it is not a reliable method to defeat an EtG test.
EtG testing is highly specific for alcohol metabolism but is not infallible. Documented sources of error include: false positives from incidental ethanol exposure (see above), sample handling errors, laboratory testing variation, and the natural biological variability in EtG production between individuals. False negatives can occur if testing happens after EtG has fully cleared, or in individuals with unusually fast glucuronidation enzyme activity. For legal or compliance purposes, a positive result typically triggers a review process rather than immediate consequence — if you believe a result is in error, you can request a split-sample confirmatory test.
A breathalyzer or blood alcohol content (BAC) test measures ethanol itself — the alcohol molecule. These tests only detect active intoxication, and ethanol clears from blood and breath within 6–12 hours of finishing drinking (at a rate of approximately 0.015 BAC per hour). EtG testing detects a metabolite produced after ethanol is processed, meaning it can reveal that someone drank alcohol 24–80 hours earlier even when they are completely sober and show no ethanol. EtG testing is specifically designed to detect past drinking events, not current impairment.
This calculator is an educational tool built on published pharmacokinetic research. It is intended to help people understand how EtG metabolism works and how long alcohol consumption is detectable. It should not be used to defeat or circumvent legitimate sobriety monitoring programs, probation requirements, workplace testing, or any other compliance obligation. The estimates produced here are approximations — individual variation means actual detection times can be longer than estimated, particularly at the 100 ng/mL cutoff or with heavy consumption.

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