ETG Calculator — Estimate How Long ETG Stays in Urine

Content reviewed for scientific accuracy by the ETG Calculator editorial team, based on guidelines from the National Institute on Alcohol Abuse and Alcoholism (NIAAA) and published toxicology research.

The ETG Calculator is a free online tool that estimates how long Ethyl Glucuronide (ETG) remains detectable in urine after alcohol consumption. Enter your drinking details, body weight, and time since your last drink to receive an estimated detection window and risk level based on commonly referenced elimination rates.

This tool is designed for educational and informational purposes only. It does not produce clinically valid measurements and cannot predict the result of a certified laboratory test.

What is ETG and why is it tested?

Ethyl Glucuronide (ETG) is a direct metabolite of ethanol — a byproduct the liver produces when it processes alcohol. Unlike alcohol itself, which clears from the bloodstream within hours, ETG remains detectable in urine for significantly longer, making it a reliable marker of recent alcohol consumption even after a person’s Blood Alcohol Concentration (BAC) has returned to zero.

ETG urine testing is used across a wide range of settings because of this extended detection window. Common applications include:

• Workplace alcohol monitoring and compliance programs
• Court-ordered sobriety monitoring and probation testing
• Inpatient and outpatient addiction recovery programs
• Clinical alcohol use disorder treatment and management
• Pre-employment and random alcohol screening programs

According to the NIAAA, alcohol metabolism occurs primarily in the liver through enzymatic pathways, with ETG forming as a minor byproduct that is then filtered into urine through the kidneys. Individual differences in liver enzyme activity, body composition, and hydration directly affect how quickly ETG clears from the system.

How the ETG calculator works

This ETG detection time calculator estimates your likely ETG concentration and detection window using a research-informed formula based on the following inputs:

• Number of standard drinks consumed — one standard drink equals approximately 14 grams of pure ethanol (12 oz beer, 5 oz wine, or 1.5 oz spirits)
• Body weight — heavier individuals distribute ethanol across a larger body mass, affecting concentration
• Biological sex — males and females differ in body water percentage and alcohol dehydrogenase enzyme activity
• Hours since last drink — ETG concentration declines over time; accuracy improves with a precise figure
• Laboratory cutoff level — the minimum ETG concentration that triggers a positive result at the testing facility

The calculator outputs an estimated ETG range in ng/mL, a risk classification (likely pass, borderline, or likely fail), and an estimated number of hours until ETG falls below your selected cutoff threshold.

ETG detection time chart

The table below shows general ETG detection windows based on drinking quantity and laboratory cutoff level. These ranges are derived from published half-life estimates and average metabolic clearance rates.

Detection windows are population averages. Individual results vary. A lower cutoff threshold means ETG remains detectable for a longer period.

ETG cutoff levels explained

Laboratory ETG tests report results against a cutoff threshold — the minimum ETG concentration required to trigger a positive result. The cutoff level used directly affects how long alcohol remains detectable:

100 ng/mL is the most sensitive threshold and is typically used in zero-tolerance programs, court-ordered monitoring, and probation compliance testing. At this level, even light alcohol consumption may be detectable for up to 36–48 hours.

300 ng/mL is the standard threshold used by most clinical and workplace testing programs. It offers a balance between sensitivity and practical detection windows.

500 ng/mL is a less sensitive threshold used in some general screening programs. It has a shorter detection window compared to lower cutoffs.

Our calculator allows you to select your applicable cutoff level so the estimate reflects the specific type of test you are being evaluated against.

Factors that affect ETG detection time

ETG detection windows vary significantly between individuals. Understanding the variables that influence clearance helps interpret estimates more accurately.

Metabolic rate — The speed at which your liver processes ethanol and eliminates ETG depends on age, genetics, fitness level, and baseline liver enzyme activity. Faster metabolism generally means a shorter detection window.

Body weight and composition — Individuals with higher body weight tend to dilute ethanol across more body mass, which can affect initial ETG production. However, body weight alone is not a reliable predictor of clearance time.

Hydration — Drinking water increases urine volume and can dilute ETG concentration in a given sample. This may lower the measured ng/mL reading but does not accelerate ETG elimination from the body. Excessive hydration can also be flagged by laboratories as sample dilution.

Drinking patterns — A single light drink produces significantly less ETG than several drinks consumed over multiple hours. Chronic or heavy drinking patterns can extend the detection window due to accumulated metabolite load.

Liver health — Conditions such as fatty liver disease, hepatitis, or cirrhosis can impair ethanol metabolism and extend how long ETG remains detectable. Certain medications that interact with liver enzyme pathways may also affect clearance.

Laboratory methodology — Different laboratories use different immunoassay panels and testing protocols. A result from one facility may not match another facility testing the same sample. Always verify the cutoff level and methodology used by your specific testing provider.

How accurate is an ETG calculator?

ETG calculators provide estimates based on population-average metabolic models. They are not diagnostic tools and cannot replicate the conditions of a certified laboratory test.

Results from this calculator may differ from actual laboratory results due to individual biological variation, differences in testing methodology, the specific cutoff level applied, and factors such as hydration or recent medication use that are not captured by the inputs.

No online ETG calculator can guarantee a negative test result. This tool is designed to help users understand how ETG detection works in general terms — not to predict the outcome of any specific test.

For any situation involving employment, legal proceedings, probation, or clinical care, always rely on certified laboratory testing and consult a qualified healthcare provider or licensed professional.

How to use this ETG calculator

1. Enter the number of standard drinks you consumed
2. Enter your body weight and select your unit (kg or lbs)
3. Select your biological sex
4. Enter the number of hours since your last drink
5. Select the ETG cutoff level that applies to your testing program (100, 300, or 500 ng/mL)
6. Click Calculate to view your estimated ETG level, risk classification, and detection window

Results appear instantly with a color-coded risk indicator and a chart showing estimated ETG decline over the next 80 hours.

Related ETG tools

All tools on this platform are free and require no registration.

• Advanced ETG Calculator — enhanced inputs for more detailed ETG level monitoring
• ETG Alcohol Urine Test Calculator — focused specifically on urine-based alcohol metabolite detection
• ETG Detection Time Calculator — estimates how long ETG remains detectable based on your drinking pattern
• ETG Half-Life Calculator — explore how ETG concentration declines over time
• ETG 100 ng/mL Calculator — check your estimate against the strictest standard threshold

Frequently asked questions about ETG testing

What is an ETG urine test? An ETG urine test detects Ethyl Glucuronide, a direct metabolite of alcohol that remains in urine significantly longer than alcohol itself. It is used to identify recent alcohol consumption even after BAC tests would return a negative result — typically in monitoring, compliance, and recovery settings.

How long does ETG stay in urine after drinking? ETG may remain detectable in urine for 24 to 80 hours after drinking, depending on the quantity consumed, individual metabolism, hydration level, and the cutoff threshold used by the testing laboratory. Heavy or prolonged drinking can extend detection beyond 80 hours in some cases.

What is the ETG half-life? ETG half-life refers to the time it takes for the ETG concentration in urine to reduce by half. Published estimates generally range from 2.5 to 5 hours, though individual variation is significant. This means ETG does not disappear suddenly — it declines gradually and predictably over time.

What are ETG cutoff levels? ETG cutoff levels are the minimum concentration thresholds that laboratories use to determine a positive result. Common levels are 100 ng/mL (high sensitivity), 300 ng/mL (standard), and 500 ng/mL (lower sensitivity). A lower cutoff means alcohol is detectable for a longer period.

Can ETG tests produce false positives? False positives are uncommon but documented. Incidental exposure to alcohol-containing products such as mouthwash, hand sanitizer, certain medications, or fermented foods has been associated with low-level ETG readings in some published cases. Most laboratory cutoffs are set to minimize this risk.

Does hydration affect ETG test results? Hydration increases urine volume and can dilute ETG concentration in a sample, potentially lowering the measured ng/mL value. However, it does not speed up ETG elimination from the body. Laboratories may flag excessively dilute samples and request a retest.

Can one drink cause a positive ETG test? At a 100 ng/mL cutoff level, a single standard drink may produce a detectable ETG result for up to 24–36 hours, depending on individual metabolism. At a 500 ng/mL cutoff, a single drink is less likely to remain detectable beyond 12–24 hours.

Is ETG testing used in court and probation programs? Yes. ETG urine testing is widely used in court-ordered sobriety monitoring, probation compliance programs, and workplace alcohol testing due to its extended detection window compared to standard BAC testing.

Can ETG be detected in blood or hair? ETG is primarily tested through urine, but it can also be detected in blood and hair samples. Blood ETG testing has a shorter detection window than urine. Hair ETG testing can detect alcohol use over a much longer period — potentially months — depending on hair length and growth rate.

Is this ETG calculator free? Yes. All tools on ETG Calculator are completely free to use and require no account creation, registration, or downloads.

Medical and legal disclaimer

The ETG Calculator and all content on this website are provided for educational and informational purposes only. Results generated by this tool are estimates based on generalized metabolic models and do not constitute medical advice, clinical guidance, or legal counsel.

ETG detection times vary significantly between individuals. No calculator can replicate a certified laboratory test or guarantee any specific outcome. Always consult a qualified healthcare professional, licensed legal advisor, or certified testing laboratory for accurate interpretation of ETG test results.

For authoritative information on alcohol metabolism and health, visit the National Institute on Alcohol Abuse and Alcoholism and the CDC Alcohol and Public Health resource center.