If you're reading this, you're probably stressed about an upcoming test. We get it—waiting and wondering can feel overwhelming.
No calculator can give you a 100% guarantee. But understanding how your body processes ETG can help you make sense of the laboratory concepts and the limits of any estimate.
The Quick Summary
Six factors determine how long alcohol stays detectable. Here's what matters most:
- The #1 Factor: How much you drank. More alcohol = much longer detection.
- Your Test Matters: A 100 ng/mL cutoff is more sensitive than 500 ng/mL.
- The Big Myth: Drinking water does NOT speed up elimination—it only dilutes your sample.
- The Reality: Your liver works at its own pace. Exercise and 'detox' drinks won't help much.
Need a number? Get an estimate based on your situation:
Quick ETG Check
Instant estimation (No data saved)
Above 500 ng/mL in the model
The model estimate sits above the common 500 ng/mL cutoff. It is educational context, not a test-result prediction.
*Educational estimate only. Individual results vary. Not medical, legal, or testing-decision advice.
This is an estimate only. Your results may vary. Not medical or legal advice.
The 6 Factors Explained
1. How Much You Drank (The Big One)
This is the most important factor—by far.
Think of your body like a bucket with a small drain hole at the bottom:
- 1-2 drinks puts a little water in. It drains quickly.
- Heavy drinking fills the bucket to the brim. It takes days to empty.
Not sure how to count drinks? Check our Standard Drink Guide. A "pint" of craft beer might actually be 2-3 standard drinks.
| Drinking Level | Peak ETG (approx.) | Estimated Time Below 500 ng/mL |
|---|---|---|
| Light (1-2) | 5,000-10,000 ng/mL | 10-13 hours |
| Moderate (3-4) | 15,000-20,000 ng/mL | 15-16 hours |
| Heavy (5-6) | 25,000-30,000 ng/mL | 17-18 hours |
| Binge (7+) | 35,000+ ng/mL | 19-25+ hours |
These are model estimates using the project's 3-hour half-life and 5,000 ng/mL peak per drink. Real-world clearance can be 20-30% longer due to individual metabolism, hydration, and body composition.
The relationship follows exponential decay: doubling your drinks adds about one extra half-life (~3 hours) to your detection window — not a doubling of the window itself.
2. Your Test's Cutoff Level
Not all ETG tests are the same. The "cutoff" is the reporting threshold used to interpret a result as negative or positive.
| Cutoff | Where It's Used | What It Means |
|---|---|---|
| 500 ng/mL | Employment, DOT | More forgiving—shorter detection window |
| 300 ng/mL | Some workplaces | Middle ground |
| 100 ng/mL | Probation, court | Very strict—much longer detection window |
Real example: After 4 drinks (peak ~20,000 ng/mL), the model says you'd cross 500 ng/mL around 16 hours and 100 ng/mL around 23 hours — a gap of roughly 7 hours where you'd be below the lenient cutoff but still above the strict one. Individual variation can shift this estimate by 20-30%.
If you don't know your cutoff, ask the testing program, lab, employer, probation officer, or legal professional before interpreting the estimate. Learn more in our ETG Test Cutoff Levels guide.
3. Your Metabolism
Your liver does the work of clearing ETG. Some livers work faster than others.
What affects your metabolism:
- Liver health — A healthy liver clears ETG efficiently
- Age — Metabolism tends to slow down after 40
- Genetics — Some people naturally produce more of the enzymes that break down ETG
The average ETG half-life is 2-3 hours, but it can range from 1.5 to 4+ hours between people. This is why calculator estimates can vary by 20-30%.
You can't change your genetics. This is one reason estimates should not be treated as guaranteed results.
4. Body Size and Composition
Alcohol distributes through body water, so your size matters.
- Heavier people have more fluid volume, which dilutes peak ETG slightly
- Women often show higher peak levels than men for the same drinks (different body water percentage)
- More muscle mass means better alcohol distribution
These effects are modest compared to drinking amount—but they add up.
5. Hydration (The "Flush" Myth)
Let's clear this up: drinking water does NOT speed up ETG elimination.
Your liver processes ETG at a fixed rate. Water doesn't change that.
What water actually does:
- Well-hydrated → More dilute urine → Lower ng/mL reading
- Dehydrated → Concentrated urine → Higher ng/mL reading
The catch: If you drink too much water before a test, your sample might be flagged as "dilute." In many probation settings, a dilute sample can create a separate compliance issue or trigger a retest.
Aim for "normally hydrated"—not water-logged.
6. Time Since Your Last Drink
ETG follows a predictable decay pattern:
- Peak: ETG levels usually peak 3-9 hours after you stop drinking
- Decay: After the peak, levels drop by roughly half every 2-3 hours
Example after 4 drinks (peak ~20,000 ng/mL):
| Hours After Peak | ETG Level | 500 ng/mL Test | 100 ng/mL Test |
|---|---|---|---|
| 6 hours | ~5,000 ng/mL | Above cutoff | Above cutoff |
| 12 hours | ~1,250 ng/mL | Above cutoff | Above cutoff |
| 18 hours | ~310 ng/mL | Below cutoff | Above cutoff |
| 24 hours | ~78 ng/mL | Below cutoff | Below cutoff |
For the math behind this, see our ETG Calculation Formula page.
Common Myths (Don't Fall For These)
❌ "I can sweat it out at the gym"
Reality: ETG is processed by your liver, not excreted through sweat. Exercise might boost your overall metabolism slightly, but it won't make a meaningful difference to your ETG level.
❌ "Detox drinks and supplements work"
Reality: No product has been proven to speed up ETG elimination. Many are expensive placebos. Some might even trigger extra scrutiny if detected.
❌ "Eating food will help"
Reality: Food slows down how fast alcohol enters your blood, but once it's there, ETG is produced regardless. Food won't reduce your detection window.
❌ "80 hours means everyone needs 80 hours"
Reality: The "80-hour window" is the maximum from heavy drinking studies. For light-to-moderate drinking, measured levels often drop below common cutoffs sooner. Individual variation still matters.
Get Your Estimate
Now that you understand the factors, see how they apply to you:
Quick ETG Check
Instant estimation (No data saved)
Above 500 ng/mL in the model
The model estimate sits above the common 500 ng/mL cutoff. It is educational context, not a test-result prediction.
*Educational estimate only. Individual results vary. Not medical, legal, or testing-decision advice.
A note on calculators: We built this tool to help you understand the science, not as timing advice for a test. Results are estimates based on averages, not guaranteed laboratory outcomes.
Related Resources
- ETG Calculator — Full calculator with all parameters
- ETG Detection Time Chart — Visual breakdown by drinks
- ETG Detection Times Explained — Detection windows in detail
- Get Help Resources — Support for alcohol concerns
Scientific References
The information on this page is based on peer-reviewed research:
- Wurst FM, et al. (2006). "Ethyl glucuronide: On the time course of excretion in urine during detoxification." Addiction Biology, 11(3):340-348.
- Helander A, Beck O. (2005). "Ethyl sulfate: A metabolite of ethanol in humans." Journal of Analytical Toxicology, 29(5):270-274.
- SAMHSA (2012). "The Role of Biomarkers in the Treatment of Alcohol Use Disorders." Advisory.
- Jatlow PI, et al. (2014). "Ethyl glucuronide and ethyl sulfate assays in clinical trials." Alcoholism: Clinical and Experimental Research, 38(7):2056-2065.
It depends on how much you drank and the test cutoff. The project's model says 1-2 drinks often fall below 500 ng/mL within 10-13 hours, and 4 drinks within about 16 hours. For 100 ng/mL probation tests, 4-12 drinks can remain above cutoff longer in the model. Individual variation can shift these estimates by 20-30%.
No. Water dilutes your urine concentration but doesn't speed up your liver. Drinking too much water can flag your sample as 'dilute,' which can create a separate compliance issue or require a retest.
How much you drank. This determines your peak ETG level, which controls how long it takes to clear. Because ETG follows exponential decay, doubling your drinks adds about one extra half-life (~3 hours) to your detection time — not a doubling of the window.
Not meaningfully. ETG is processed by your liver at a relatively fixed rate. Working out won't speed this up enough to matter for test timing.
Because it detects trace amounts. For 4 drinks, the model says the estimate crosses 500 ng/mL around 16 hours but remains above 100 ng/mL until about 23 hours — a 7-hour gap. The same drinking episode can show positive longer on sensitive tests, and individual variation can stretch the gap further.
They're reasonable estimates based on research averages. But individual metabolism varies by 20-30%, so treat results as educational guidelines, not guarantees.
This page is for educational purposes only. It does not constitute medical or legal advice. Individual metabolism varies significantly. Consult a healthcare provider or legal professional for guidance specific to your situation.