EtG Calculator

What This EtG Calculator Does

This tool estimates how long ethyl glucuronide (EtG) — a direct metabolite of ethanol — may remain detectable in urine after alcohol consumption. It calculates detection windows based on the time elapsed since your last drink and common testing cutoff thresholds used in laboratory analysis.

EtG testing is highly sensitive and can detect alcohol consumption for a longer period than traditional ethanol tests. This calculator helps you understand the approximate detection timeframe under standard testing conditions.

How the Detection Window Is Calculated

The calculator uses established pharmacokinetic data on EtG elimination. After alcohol is metabolized, EtG is formed and excreted in urine. Its detection window depends primarily on two factors:

• Time since last alcohol consumption — the starting point for the elimination clock
• Test cutoff threshold — the concentration level (typically 100 ng/mL, 500 ng/mL, or 1000 ng/mL) that determines a positive result

Higher cutoff thresholds result in shorter detection windows because lower EtG concentrations are not reported as positive. Lower cutoffs extend the window by capturing trace amounts that persist longer.

The estimates assume normal hydration, average metabolism, and single-episode alcohol use. Individual variation can affect actual detection times.

How to Use the Calculator

1. Enter the number of hours since you last consumed alcohol.
2. Select the test cutoff threshold that applies to your situation (100, 500, or 1000 ng/mL).
3. Review the estimated detection window and whether you fall within or outside the typical positive range.

The result indicates whether EtG is likely detectable at the chosen cutoff based on standard elimination curves.

Understanding the Results

The output shows one of three possible statuses:

• Likely detectable — your time since drinking falls within the typical window for the selected cutoff.
• Borderline — you are near the edge of the detection window. Results may vary based on individual factors.
• Unlikely detectable — sufficient time has passed that EtG concentration is likely below the cutoff threshold.

These estimates are based on population averages. Actual results depend on metabolic rate, hydration status, frequency of alcohol use, and individual physiology.

Common Misconceptions About EtG Detection

• EtG does not measure intoxication. It only indicates that alcohol was consumed within the detection window.
• Detection time is not the same for everyone. Heavy or chronic alcohol use can extend detection windows beyond standard estimates.
• Hydration affects concentration. Dilute urine may lower EtG levels, but laboratories can adjust for this.
• Cutoff thresholds matter significantly. A 100 ng/mL cutoff detects alcohol much longer than a 1000 ng/mL cutoff.

Limitations of This Estimate

This calculator provides an approximation, not a guarantee. Actual EtG detection depends on multiple variables not captured here, including:

• Individual metabolic rate and liver function
• Amount and type of alcohol consumed
• Frequency of alcohol use (chronic vs. occasional)
• Hydration status and urine dilution
• Time of day and kidney function

For legal or clinical purposes, always consult a qualified professional and rely on actual laboratory test results rather than estimates.

Practical Use Cases

• Understanding testing timelines — individuals subject to EtG monitoring can better understand detection windows.
• Educational reference — clinicians and counselors can use the tool to explain EtG testing parameters.
• Self-assessment context — provides a general timeframe reference, not a substitute for professional advice.