Alcohol ETG Calculator
How long does alcohol show in an ETG test? Enter your drinks and timing — this alcohol ETG calculator estimates hour-by-hour detection windows at 500 ng/mL and 100 ng/mL cutoffs.
Calculate Your ETG Level
Enter your drinking details for an instant estimate
Estimated ETG Level
until the model is below this line
Common workplace line
until the model is below this line
Common probation / court line
Estimates only. Individual metabolism varies significantly. This is not medical or legal advice.
What this number means
The tool opens on 3 standard drinks and 12 hours. That run is about 938 ng/mL. In this model that sits above both the 500 and the 100 ng/mL lines.
- 500 ng/mL is the line many workplace programs use.
- 100 ng/mL is the stricter probation / court line.
- A number between them can sit under 500 and still sit over 100.
When this calculator does not apply
- This is a model estimate, not a lab printout. It cannot say what a program will do with a real sample.
- The 100 and 500 lines here are common cutoffs, not your paperwork. If the form lists another number, that number wins.
- The hours under each cutoff are when this formula drops below that line. They are not a time to go get tested.
Same numbers as the default run: 3 drinks, 12 hours
- 3 standard drinks. Peak: 3 × 5,000 = 15,000 ng/mL
- 12 hours later is 4 half-lives. 15,000 × 0.5⁴ = 938 ng/mL
- 938 sits above 500 and above 100
- The model falls below 500 about 3 hours after this point, and below 100 about 10 hours after this point
ETG(t) = Peak × 0.5^(t / half-life)Peak is 5,000 ng/mL per standard drink. Half-life is 3 hours. Those are this site's model assumptions, taken from published ETG half-life work and common SAMHSA cutoff numbers, not your lab's method.
Where the estimate sits
Estimated ETG level is below even the strictest 100 ng/mL cutoff (used in probation and court-ordered programs)
Could fall below a 500 ng/mL cutoff while still exceeding stricter monitoring cutoffs
Estimated ETG level is above the 500 ng/mL cutoff used by many workplace and pre-employment drug screenings
Estimated ETG level is well above common cutoffs, often associated with heavier or more recent drinking
Research Sources
- Wurst FM et al. (2006) 'Ethyl glucuronide — update' Forensic Science International
- SAMHSA Guidelines for ETG/ETS Testing
- Helander A, Beck O (2005) 'Ethyl sulfate: a metabolite of ethanol' Clinical Chemistry
Other runs with the same formula
These use the same 5,000 ng/mL peak and 3-hour half-life as the tool. Change the sliders to the same drinks and hours if you want to see the number appear above.
Sunday BBQ, Monday 8am
4 standard beers, last drink around 6pm Sunday.
Above 500 ng/mL in the model
Friday dinner, Monday morning
2 glasses of wine Friday night, nothing else all weekend.
Below both common cutoffs in the model
Saturday wedding, Sunday night
About 8 standard drinks, stopped around midnight.
Below 500 ng/mL, still above 100
Thursday drinks, Monday 9am
3 standard drinks Thursday evening.
Below both common cutoffs in the model
These numbers come from the formula on this page. Real samples move with metabolism, cutoff, and lab method.
Why Use an Alcohol ETG Calculator?
Unlike breathalyzers that only detect current intoxication, an alcohol ETG calculator helps you understand how long alcohol metabolites stay in your system. ETG (Ethyl Glucuronide) is a direct biomarker your liver produces when processing alcohol — and it sticks around for days.
This matters because many testing programs specifically look for ETG, not just alcohol itself. Whether you're facing a probation test, workplace screening, or court-ordered monitoring, knowing your estimated ETG level can help you make informed decisions about timing.
Key differences from other alcohol tests:
- Breathalyzer: Only detects active intoxication (hours)
- Blood test: Detects alcohol for 12-24 hours
- ETG urine test: Detects alcohol use for 24-80+ hours
Our calculator uses the same half-life formula used in forensic toxicology research. While individual results vary based on metabolism, body weight, and liver health, this gives you a science-based starting point for understanding your risk level.
How to Use
- 1
Count your total standard drinks. One drink = 12oz regular beer, 5oz wine, or 1.5oz spirits. Strong beers and large pours count as more.
- 2
Enter hours since you finished drinking. Not when you started — when you had your last sip.
- 3
Check your estimated ETG level and cutoff category. Red = above 500 ng/mL in the model, green = below 100 ng/mL in the model.
- 4
Compare the estimate against both common cutoffs: standard (500ng) for many workplace tests, strict (100ng) for some monitoring programs.
- 5
Treat the estimate as educational context. Your body, sample conditions, and testing program rules can change real-world interpretation.
Frequently Asked Questions
It depends on how much you drank. Light drinking (1-2 drinks) is often below common cutoffs in 12-24 hours. Moderate drinking (3-5 drinks) can remain detectable for 24-48 hours. Heavy drinking (6+ drinks) can remain detectable for 48-72 hours or more. The often-quoted '80 hours' is an extreme case. Use the calculator above for an educational estimate, not a guaranteed result.
What matters is the amount of pure alcohol, not the drink type. Your body produces the same ETG whether you drink beer, wine, or spirits. What counts is 'standard drinks': one 12oz beer equals one 5oz glass of wine equals one 1.5oz shot. A strong craft beer (8% ABV) counts as about 1.5 standard drinks. A large pour of wine might be 2 drinks. Count carefully.
When you drink, your liver breaks down alcohol (ethanol) into various byproducts. One of these is ETG (ethyl glucuronide) — think of it as alcohol's 'fingerprint' that sticks around after the alcohol itself is gone. Your body produces peak ETG levels about 2-3 hours after drinking, then it gradually decreases with a half-life of roughly 3 hours. That's why ETG tests can catch drinking from days ago, not just current intoxication.
Several factors influence your personal ETG decline rate: body weight (larger people generally process faster), liver health, hydration level, food intake, genetics, and age. Women typically have higher peak ETG levels than men for the same amount of alcohol. Chronic heavy drinkers may have altered metabolism. The calculator uses research averages — your actual results could be 20-30% different.
No — water doesn't speed up ETG metabolism. Your liver processes ETG at a relatively fixed rate regardless of hydration. Water can dilute your urine sample, which labs may flag as 'dilute' or invalid depending on the program. Stay normally hydrated and rely on the testing program or lab for interpretation.
Yes, this is real. Alcohol-based hand sanitizers, certain mouthwashes, some medications, and even vanilla extract can introduce alcohol to your system and cause positive ETG readings. However, these typically produce low levels (under 500ng/mL). Most standard tests use 500ng as the cutoff specifically to filter out 'incidental exposure.' If you're on strict 100ng monitoring, avoid all alcohol-containing products and check medication labels.
Related Tools
ETG Urine Test Calculator
Our main ETG detection tool
ETG Detection Time Chart
Visual breakdown by drinks
ETG Detection Times Explained
Understand detection windows by amount
ETG Cutoff Levels
Compare 100, 200, 300, and 500 ng/mL thresholds
ETG Calculation Formula
The science behind the math
ETG Half-Life Calculator
Visualize decay over time
Standard Drink Guide
Know exactly what counts as one drink
This calculator provides estimates for educational purposes only — not medical or legal advice. Individual metabolism varies significantly. Don't base important decisions solely on this tool. For case-specific testing questions, consult a healthcare provider, legal professional, lab, or testing program.