Health
Estimate a urine EtG detection window by standard drinks, elapsed time, drinking pattern, and the cutoff your test uses.
About this calculator
Estimates the window of time during which ethyl glucuronide (EtG) may remain detectable in urine after alcohol consumption. The estimate adjusts based on the number of standard drinks, the drinking pattern (single session, extended window, or heavy binge), the hours elapsed since the last drink, and the test cutoff level in ng/mL.
Individuals who want a rough, research-informed estimate of how long EtG might stay detectable in their system after drinking, based on their specific consumption pattern and the cutoff threshold their test uses.
Select a drinking pattern and enter the number of standard drinks consumed and the hours since your last drink. Choose a cutoff level (100, 250, or 500 ng/mL, or a custom value) that matches your test's threshold. The calculator computes a likely-negative time and a more conservative upper bound, a risk band, and a comparison across all three standard cutoff levels so you can see how cutoff sensitivity affects the window.
This is a rough estimate only and must not be treated as a guarantee of passing or failing any test. Individual factors — metabolism, hydration, liver function, body mass, genetics, and lab method variability — can significantly affect actual detection times. Incidental non-beverage alcohol exposure (mouthwash, hand sanitizer, certain foods) may also matter at lower cutoffs.
Formula
The initial detection window is estimated from the number of standard drinks processed through a simplified pharmacokinetic model. Each standard drink adds roughly 12–24 hours to the potential detection window depending on the drinking pattern.
The drinking pattern modulates the baseline estimate. Single-session drinks are concentrated in a short window, extending the peak EtG level. Extended-window drinks spread metabolism over time, shortening the tail. Heavy-binge sessions produce a higher peak and longer overall detection curve.
Higher cutoffs (500 ng/mL) produce shorter detection windows because only higher metabolite concentrations register as positive. Lower cutoffs (100 ng/mL) are more sensitive and produce longer windows. The calculator adjusts estimates proportionally using established reference ratios.
Hours since last drink are subtracted from the raw estimate to produce a remaining window. If elapsed time exceeds the estimated window, the result shows the subject is already past the likely detection range.
How it works
Step 1
Choose Single Session for drinks consumed within 1–2 hours, Extended Window for drinks spread across many hours, or High-Intensity for sustained high-volume sessions. The pattern adjusts the peak EtG concentration and elimination curve.
Step 2
Enter the total number of standard drinks consumed (12 oz beer, 5 oz wine, or 1.5 oz spirits = 1 standard drink). Be as accurate as possible — this is a primary driver of the detection window.
Step 3
Input the number of hours that have passed since you finished your last drink. This is subtracted from the raw estimate to determine the remaining detection window.
Step 4
Select 100, 250, or 500 ng/mL to match your test, or choose Custom to enter a specific cutoff between 50 and 1000 ng/mL. Lower cutoffs produce longer detection windows.
Step 5
Read the likely-negative hours (when you will probably test below cutoff) and the conservative estimate (a more cautious upper bound). The preset comparison cards show how different cutoffs change the window.
Step 6
The risk band (Low, Borderline, or High) gives a quick summary of where you fall relative to the chosen cutoff. Use the summary text for context about your specific inputs.
Reference ranges
Typical detection window of 24–48 hours at 500 ng/mL cutoff, extending to 48–72 hours at 100 ng/mL. Light to moderate drinking in a short period produces the shortest overall detection times.
Typical detection window of 36–60 hours at 500 ng/mL cutoff, extending to 60–80 hours at 100 ng/mL. Drinking spread over many hours produces a flatter but longer elimination curve.
Typical detection window of 48–72 hours at 500 ng/mL cutoff, extending to 72–96 hours at 100 ng/mL. High-volume sessions produce the highest peak metabolite levels and the longest detection windows.
The 500 ng/mL cutoff is the least sensitive and produces the shortest windows. 250 ng/mL is a common intermediate threshold. 100 ng/mL is the most sensitive and produces the longest windows. Laboratory policies on reporting positive vs. negative vary and affect real-world results.