EtG Calculator: Urine Alcohol Clearance & Decay Curve
Estimate Ethyl Glucuronide (EtG) elimination half-life, hours to clean, and probation test cutoff risk.
Urinary Ethyl Glucuronide (EtG) exhibits an average biological half-life of 2.5 to 3.0 hours, peaking between 4 and 6 hours after alcohol consumption. Light alcohol intake (1–2 standard drinks) clears below the 500 ng/mL clinical cutoff within 24 to 36 hours, while moderate to heavy drinking (4–8 drinks) requires 48 to 72 hours to clear zero-tolerance 100 ng/mL probation screens.
⚡ 2026 EtG Urine Alcohol Clearance & Decay Calculator
729 ng/mL
Target Cutoff: 100 ng/mL | Peak Level: ~102,984 ng/mL
EtG Clearance Timeline & Excretion Decay Table
Unlike blood alcohol concentration (BAC) which dissipates at roughly 0.015% per hour, Ethyl Glucuronide is a non-oxidative direct metabolite of ethanol conjugated in the liver with glucuronic acid. Below is the clinical decay reference table across varying intake levels:
| Intake Level (Standard Drinks) | Peak Urinary EtG (ng/mL) | Hours to Clear 500 ng/mL | Hours to Clear 100 ng/mL |
|---|---|---|---|
| 1–2 Drinks (e.g. 2 beers) | 15,000 – 35,000 | ~18 – 24 hours | ~28 – 36 hours |
| 3–5 Drinks (Moderate) | 45,000 – 90,000 | ~30 – 40 hours | ~42 – 52 hours |
| 6–10 Drinks (Heavy Binge) | 100,000 – 250,000+ | ~44 – 56 hours | ~58 – 72 hours |
Understanding the 100 ng/mL vs. 500 ng/mL Cutoff Thresholds
In forensic toxicology, the selection of the cutoff threshold determines the evidentiary weight of an EtG test. According to the Substance Abuse and Mental Health Services Administration (SAMHSA) Advisory:
- 500 ng/mL Benchmark: The standard clinical cutoff for substance use monitoring. This cutoff effectively filters out incidental environmental exposure from hand sanitizers, hygiene products, fermented condiments (soy sauce, kombucha), and non-alcoholic beers containing trace ethanol.
- 100 ng/mL Zero-Tolerance Cutoff: Often adopted in high-scrutiny probation or child custody settings. However, SAMHSA cautions that readings between 100 and 500 ng/mL cannot reliably confirm intentional beverage consumption and should always be corroborated with a secondary Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) assay.
Frequently Asked Questions
How long does EtG stay in urine after drinking?
For light drinking (1-2 drinks), urinary EtG drops below the 500 ng/mL clinical cutoff in 24 to 36 hours. For heavy binge drinking (6+ drinks), EtG can remain detectable at strict 100 ng/mL probation thresholds for 48 to 72 hours. Peak EtG production occurs roughly 4 to 6 hours after the last drink.
What is the difference between a 100 ng/mL and 500 ng/mL EtG cutoff?
SAMHSA guidelines established the 500 ng/mL cutoff to minimize false positives from incidental contact (such as mouthwash, hand sanitizers, or fermented foods). A 100 ng/mL cutoff is used in strict court monitoring and probation, but carries a high rate of incidental false positives.
Can mouthwash or hand sanitizer cause a false positive EtG test?
Yes. Repeated use of alcohol-based mouthwashes or heavy aerosol hand sanitizer exposure can produce urinary EtG concentrations between 50 and 300 ng/mL. If facing an unconfirmed 100 ng/mL screen, request a confirmatory LC-MS/MS test paired with Ethyl Sulfate (EtS).