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.

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Calculate Your ETG Level

Enter your drinking details for an instant estimate

Likely Detected
1 drink = 12oz beer, 5oz wine, 1.5oz spirits
Time elapsed since you stopped drinking
~938 ng/mL

Estimated ETG Level

500ng
01500+
Standard Cutoff (500ng)
3h

Employment / Driving tests

Strict Cutoff (100ng)
10h

Probation / Court-ordered tests

Estimates only. Individual metabolism varies significantly. This is not medical or legal advice.

How ETG Calculation Works

ETG(t) = Peak × 0.5^(t / half-life)

ETG (Ethyl Glucuronide) is what your body creates after processing alcohol. Unlike a breathalyzer that only catches you when actively drunk, ETG stays in your urine for days — that's why it's used for probation and workplace testing.

Your ETG level drops by half roughly every 3 hours. So if you start at 10,000 ng/mL, you'll be around 5,000 after 3 hours, then 2,500 after 6 hours, and so on.

Everyone metabolizes alcohol differently. Your liver speed, body weight, hydration, and even genetics all play a role. Our calculator uses averages from medical research — your actual numbers could be 20-30% higher or lower.

Example: 4 Drinks on a Saturday Night

  • 4 standard drinks (stopped at midnight)
  • Peak ETG: ~20,000 ng/mL
  • Sunday noon (12h later): ~1,250 ng/mL — above common cutoffs
  • Monday morning (32h later): ~78 ng/mL — below 100 ng/mL in the model

ETG Cutoff Levels Explained

<100 ng/mLBelow Strict Cutoff

Estimated ETG level is below even the strictest 100 ng/mL cutoff (used in probation and court-ordered programs)

100-500 ng/mLGray Zone

Could fall below a 500 ng/mL cutoff while still exceeding stricter monitoring cutoffs

500-1000 ng/mLAbove Standard Cutoff

Estimated ETG level is above the 500 ng/mL cutoff used by many workplace and pre-employment drug screenings

>1000 ng/mLHigh Estimate

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

Real-World Scenarios

These examples show what typical results look like. Your numbers will vary based on your body, but this gives you a realistic idea of what to expect.

The Monday Morning Test

4 beers at a Sunday BBQ with friends, stopped drinking around 6pm. Boss schedules a random test for Monday 8am.

Time:14 hours later
Level:~1,250 ng/mL

Above standard cutoff in the model

The Friday Happy Hour

2 glasses of wine at dinner Friday night, nothing else all weekend. Scheduled test Monday morning.

Time:60+ hours later
Level:<50 ng/mL

Below 100 ng/mL in the model

The Wedding Weekend

Open bar at a Saturday wedding — you lost count after 8 drinks. Test scheduled for Wednesday.

Time:~80 hours later
Level:~100-200 ng/mL

Below 500 ng/mL, near stricter cutoffs

The Random Work Test

3 drinks at Thursday happy hour. HR emails Friday afternoon: 'Report for testing Monday 9am.'

Time:~62 hours later
Level:<100 ng/mL

Below both common cutoffs in the model

Remember: these are estimates based on average metabolism. Some people metabolize faster, some slower. Use the examples to understand cutoff context, not to guarantee a result.

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. 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. 2

    Enter hours since you finished drinking. Not when you started — when you had your last sip.

  3. 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. 4

    Compare the estimate against both common cutoffs: standard (500ng) for many workplace tests, strict (100ng) for some monitoring programs.

  5. 5

    Treat the estimate as educational context. Your body, sample conditions, and testing program rules can change real-world interpretation.

Frequently Asked Questions

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.