EtG Detection Time Calculator: Hours to Clearance
The 80-hour rule is misleading because actual EtG detection time depends on drinking amount, body weight, timing, and cutoff. This calculator gives an hour-by-hour estimate for your specific scenario.
Editorial note
This educational page is maintained by EtGCalc and reviewed against published EtG research, SAMHSA guidance, and our calculator methodology. It does not provide medical or legal advice.
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How to Use This Calculator
Enter your sex, weight, drink count, drink type, and time since your last drink. The calculator estimates your EtG level and compares it with common 100 ng/mL and 500 ng/mL cutoffs. For a broader explanation, read our EtG calculation guide.
1The 80-Hour Myth Busted
EtG can be detectable for up to 80 hours in some heavy-use scenarios, but that is not the typical result for every person or every drinking event.
Detection time is a curve, not a fixed rule. Light drinking at a 500 ng/mL cutoff can clear much sooner than heavy drinking at a 100 ng/mL cutoff.
Better than a rule of thumb
A personalized estimate beats generic 24-hour, 48-hour, or 80-hour guesses.
2Detection Time by Drinking Amount
The more alcohol consumed, the higher the estimated peak EtG. A higher peak requires more half-lives before the level falls below the cutoff.
That is why the same person can have a short detection window after two drinks and a much longer one after binge drinking.
- Low intake: lower peak, shorter modeled window
- Moderate intake: cutoff becomes important
- Heavy intake: longer tail and more uncertainty
3Why the Calculator Beats Generic Charts
Generic charts cannot know your weight, sex, drinking amount, time since last drink, or cutoff. The calculator uses those inputs to produce a more relevant estimate.
The result is still not a guarantee, but it is a better planning tool than a universal detection window.
- Personalized inputs
- 100 and 500 ng/mL cutoff context
- Private browser-based calculation
Detection Window Reference
| Scenario | Estimate | Context |
|---|---|---|
| Light drinking | Often 12-24h | At standard cutoff |
| Moderate drinking | Often 24-48h | Depends heavily on cutoff |
| Heavy drinking | 48h+ | Can extend longer |
| Strict 100 cutoff | + several hours | Longer than 500 cutoff |
Frequently Asked Questions
Is EtG always detectable for 80 hours?
No. The 80-hour number is a maximum-type scenario, not a universal detection rule.
What is the fastest EtG can clear?
Light drinking may fall below standard cutoffs within a day, but individual results vary.
Why does 100 ng/mL last longer?
It is a stricter cutoff, so the test keeps detecting lower residual levels.
Does the calculator show exact test results?
No. It estimates likely concentration based on average kinetics.
What should I use for last drink time?
Use the time you finished your final drink, not when you started drinking.
Other EtG Calculator Tools
Medical & Legal Disclaimer
Not Medical Advice
EtGCalc does not provide diagnosis, treatment, or medical advice. Talk with a qualified healthcare provider about alcohol use, metabolism, testing concerns, or recovery.
Not Legal Advice
EtG testing can affect probation, custody, licensing, and employment decisions. Consult a licensed attorney or your testing program for legal questions.
If You Need Support
In the United States, SAMHSA's National Helpline is 1-800-662-4357. It is free, confidential, and available 24/7.
Calculator output is an estimate, not a test prediction. Individual metabolism, hydration, kidney function, genetics, specimen handling, and lab cutoff policy can change real results. See our methodology and sources.
References
- 1SAMHSA. The Role of Biomarkers in the Treatment of Alcohol Use Disorders, 2012 Revision.
Used for biomarker context, cutoff interpretation, and incidental exposure cautions.
- 2Jatlow et al. Ethyl glucuronide and ethyl sulfate assays in clinical trials, 2014.
Used for urinary EtG and EtS kinetics after alcohol exposure.
- 3McDonell et al. Using ethyl glucuronide in urine to detect alcohol use, 2015.
Used for EtG detection window context in clinical monitoring populations.
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