Etg Calculator

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EtG Alcohol Level Calculator

Estimate Ethyl Glucuronide levels and detection windows

(1 drink = 12oz beer, 5oz wine, or 1.5oz liquor)
Time elapsed since alcohol consumption ended
2 Hours (Fast Metabolism) 2.5 Hours (Average) 3 Hours (Slow Metabolism) The time it takes for EtG levels to reduce by half in the urine.

Estimated Results

Understanding EtG Testing

Ethyl Glucuronide (EtG) is a direct metabolite of ethanol that is used as a marker for recent alcohol consumption. Unlike blood alcohol concentration (BAC), which returns to zero relatively quickly, EtG remains detectable in urine for a significantly longer period, often making it the preferred test for abstinence monitoring.

How This Calculator Works

This calculator uses a pharmacokinetic decay model to estimate your EtG levels. It assumes a peak EtG concentration based on the number of standard drinks consumed and then applies a half-life formula to determine the remaining concentration after a specific number of hours.

Note: 1 standard drink is approximately 14 grams of pure alcohol. Peak EtG can reach roughly 50,000 ng/mL per standard drink in a concentrated urine sample.

Common EtG Cut-off Levels

Lab tests typically use specific "cut-off" thresholds to determine a positive result. These thresholds help filter out "incidental exposure" (like using hand sanitizer or mouthwash):

  • 100 ng/mL: Highly sensitive; often used to detect incidental exposure or very light consumption.
  • 500 ng/mL: Standard forensic cut-off; highly indicative of recent drinking (within 1-3 days).
  • 1000 ng/mL: Conservative cut-off; confirms heavy drinking or very recent consumption.

Factors Influencing EtG Decay

No calculator can provide 100% accuracy because human biology varies. Your actual EtG level is affected by:

  • Hydration: High water intake can dilute urine, lowering the measured ng/mL.
  • Liver Function: Metabolism speed dictates how fast EtG is created and excreted.
  • Body Mass: Volume of distribution affects the initial peak concentration.
  • Frequency of Use: Chronic heavy drinkers may have different metabolic patterns.

The "80-Hour" Myth

While EtG is often called the "80-hour test," most people fall below the standard 500 ng/mL cut-off much sooner (typically 24–48 hours) after moderate consumption. The 80-hour window usually applies only to extreme cases of binge drinking or very low cut-off levels (100 ng/mL).

function calculateEtG() { var drinks = parseFloat(document.getElementById('numDrinks').value); var hours = parseFloat(document.getElementById('hoursElapsed').value); var hl = parseFloat(document.getElementById('halfLife').value); var resultDiv = document.getElementById('etgResult'); var valueDiv = document.getElementById('etgValue'); var statusDiv = document.getElementById('etgStatus'); if (isNaN(drinks) || isNaN(hours) || isNaN(hl) || drinks < 0 || hours < 0) { alert("Please enter valid positive numbers."); return; } // Mathematical Model: // Peak EtG is estimated at roughly 50,000 ng/mL per standard drink. // This is an average based on concentrated urine samples. var peakEtG = drinks * 50000; // Half-life formula: N(t) = N0 * (1/2)^(t/h) var currentEtG = peakEtG * Math.pow(0.5, (hours / hl)); // Formatting the output var formattedEtG = Math.round(currentEtG).toLocaleString(); resultDiv.style.display = 'block'; valueDiv.innerHTML = formattedEtG + " ng/mL"; if (currentEtG >= 500) { resultDiv.style.background = '#f8d7da'; resultDiv.style.border = '1px solid #f5c6cb'; statusDiv.style.color = '#721c24'; statusDiv.innerHTML = "LIKELY POSITIVE (Standard 500 ng/mL Cut-off)"; } else if (currentEtG >= 100) { resultDiv.style.background = '#fff3cd'; resultDiv.style.border = '1px solid #ffeeba'; statusDiv.style.color = '#856404'; statusDiv.innerHTML = "BORDERLINE / POSITIVE (Low 100 ng/mL Cut-off)"; } else { resultDiv.style.background = '#d4edda'; resultDiv.style.border = '1px solid #c3e6cb'; statusDiv.style.color = '#155724'; statusDiv.innerHTML = "LIKELY NEGATIVE (At 100/500 ng/mL Thresholds)"; } }

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