ETG Detection Time Calculator

Alcohol tests don't all measure the same thing. A breathalyzer tells you about the alcohol in your system right now, but an EtG test can flag drinking that happened one, two, even three days ago. That gap is exactly why the ETG Detection Time Calculator above exists: to give you a clear, research-based estimate of how long ethyl glucuronide might still show up in a urine test, based on what you drank, your body weight, and how much time has already passed.

This guide walks through what EtG actually is, what shifts your personal detection window longer or shorter, how to read the calculator's results, and answers to the questions people ask most often about EtG testing.

What Is EtG and Why Does It Matter?

EtG stands for ethyl glucuronide, a byproduct your liver creates as it breaks down ethanol (the alcohol in beer, wine, and spirits). Unlike alcohol itself, which clears from your blood within a matter of hours, EtG lingers in urine much longer, which is exactly why it became the go-to marker for extended-window alcohol testing.

You'll typically encounter EtG testing in a few specific settings:

• Court-ordered sobriety monitoring or probation compliance
• Substance abuse treatment and recovery programs
• Workplace testing in safety-sensitive roles
• Child custody or family court proceedings
• Medical monitoring where alcohol use affects treatment (liver conditions, certain medications, organ transplant lists)

Because EtG testing is designed to catch alcohol use that a standard breathalyzer would miss entirely, the detection window is the whole point, and it's also the part people most often get wrong. That's the gap this calculator is built to close.

How the ETG Detection Time Calculator Works

The calculator doesn't use a single fixed number like "EtG lasts 80 hours." Instead, it builds an estimate from the same variables that clinical drinking studies actually measured:

• Body weight – a smaller frame concentrates the same amount of alcohol into a smaller volume, extending the window
• Biological sex – differences in body water distribution mean the same drink amount tends to produce a higher peak concentration in women than in men
• Number of drinks, volume, and alcohol percentage – together these calculate your total grams of pure alcohol consumed
• Food intake – drinking on an empty stomach raises peak concentration compared to drinking with a meal
• Hours since your last drink – so the result reflects time remaining, not just a window starting from zero

From there, it converts your inputs into alcohol dose per kilogram of body weight and maps that figure against published EtG detection-window ranges for both standard (500 ng/mL) and low-cutoff (100 ng/mL) urine tests.

Standard Cutoff vs. Low Cutoff EtG Tests, Explained

One detail trips up almost everyone researching EtG testing: not all EtG tests use the same sensitivity, and that difference changes the detection window dramatically.

Standard Cutoff Test (500 ng/mL)

This is the less sensitive threshold, generally used to confirm heavier or more recent drinking. It typically only flags alcohol use within roughly the past 12 to 36 hours.

Low Cutoff Test (100 ng/mL)

This is a far more sensitive threshold, capable of picking up trace amounts of EtG well after the standard test would read negative. Depending on the amount consumed, this can extend the detectable window to 48, 72, or even up to around 80 to 90 hours after heavy drinking.

This is exactly why the calculator shows two separate results rather than one. A result that reads "likely negative" on the standard test can still read "likely positive" on a low-cutoff test at the same point in time.

Factors That Affect Your EtG Detection Time

1. How much you drank

This is the single biggest factor. Total alcohol dose, not just number of drinks, drives detection time. Three shots of a strong spirit will produce a longer window than three light beers.

A note on drinking level terms used in this Core article: Binge drinking brings a person’s blood alcohol concentration to 0.08% or more, which typically happens if a woman has 4 or more drinks, or a man has 5 or more drinks, within about 2 hours. Heavy drinking includes binge drinking and has been defined for women as 4 or more drinks on any day or 8 or more per week, and for men as 5 or more drinks on any day or 15 or more per week. “High intensity drinking” is defined as drinking at two or more times the binge drinking thresholds, that is, 8 or more drinks on an occasion for women or 10 or more for men.

2. Body weight and composition

Alcohol distributes through body water. Less body water relative to weight means a higher concentration for the same amount consumed, which extends the window.

3. Biological sex

Women generally have a lower body water percentage than men of similar weight, which tends to produce a higher peak concentration, and therefore a longer detection window, for an identical amount of alcohol.

4. Hydration and urine concentration

Very dilute urine can sometimes push EtG below a lab's cutoff earlier than expected, while concentrated urine can extend apparent detection. This is one of the biggest sources of real-world variability.

5. Liver function and metabolism

Since EtG is a byproduct of alcohol metabolism, anything that affects liver processing speed, including age, liver health, and certain medications, can shift detection time in either direction.

6. Food intake

Eating before or while drinking slows alcohol absorption and tends to lower peak concentration, which can shorten the detection window slightly compared to drinking on an empty stomach.

7. The specific lab and assay used

Different labs may use different EtG cutoff levels, so two people with an identical drinking history could get different results depending on which threshold the testing facility applies.

How to Use the ETG Detection Time Calculator

1. Enter your body weight and select your biological sex.
2. Enter the number of drinks you had, the volume per drink, and the alcohol percentage. Use the quick-select chips for common drinks like beer, wine, or spirits if you're not sure of exact numbers.
3. Select whether you ate before or during drinking.
4. Enter how many hours have already passed since your last drink.
5. Select "Calculate detection window" to see your estimated remaining window for both the standard and low-cutoff tests, along with a status showing whether you're likely to test positive, borderline, or likely negative at this point in time.

General EtG Detection Time Reference

These figures are general reference points only. Your actual results from the calculator above will adjust for your specific weight, sex, food intake, and elapsed time.

Frequently Asked Questions About EtG Testing

How long does EtG stay in your urine?

Typically between 12 and 36 hours on a standard cutoff test, and up to 72 to 90 hours on a low-cutoff test after heavy drinking. The exact time depends on how much you drank, your body weight, hydration, and metabolism.

Can one drink cause a positive EtG test the next day?

Yes, particularly on a low-cutoff test. A single drink can sometimes still be detectable 20 or more hours later, though a standard cutoff test is less likely to flag such a small amount after that much time.

Is the ETG Detection Time Calculator accurate?

The calculator is built on dose-response patterns from controlled drinking research and gives a well-grounded estimate, but no calculator can predict an exact lab result. Hydration, individual metabolism, and the specific assay used at the testing facility all introduce real variability.

Does hand sanitizer or mouthwash cause a false positive EtG test?

Products containing ethanol, including some mouthwashes, hand sanitizers, and cooking with alcohol, can in rare cases contribute trace EtG, particularly on very sensitive low-cutoff tests. This is a known limitation of EtG testing and one reason results are sometimes interpreted cautiously.

What's the difference between an EtG test and a breathalyzer?

A breathalyzer measures active alcohol in your breath and reflects intoxication in real time, typically clearing within hours. An EtG test measures a metabolic byproduct in urine and is designed specifically to detect drinking that happened well after you're no longer intoxicated.

Does drinking water speed up EtG elimination?

Staying hydrated supports normal kidney function, but it does not meaningfully speed up how quickly your liver processes alcohol into EtG or clears it from your system. Very dilute urine can sometimes affect test readings, which is why some labs also check creatinine levels to flag unusually diluted samples.

Important Disclaimer

This calculator and guide are provided for educational purposes only. They are not a substitute for medical, legal, or professional advice, and should not be used to predict, guarantee, or influence the outcome of an actual drug or alcohol test. EtG detection times vary significantly between individuals due to metabolism, hydration, liver function, and the specific testing method used. If you have questions about an upcoming test or a medical concern related to alcohol use, speak with a qualified healthcare provider, legal professional, or your testing program directly.