Etg Calculator - Urine EtG and Detection Time

An EtG calculator estimates how much ethyl glucuronide (EtG) is still in your urine after drinking and predicts when that level will fall below common urine assay cutoffs, so the underlying alcohol pharmacokinetics is easier to translate into a quantitative number for learning, clinical conversation, or general planning.

• • Learn alcohol pharmacokinetics: Watch how total alcohol mass, body water, gender, and elapsed time change the modeled urine EtG level, so the result makes sense regardless of the reason for testing.
• • Frame a clinical conversation: Bring a clear set of inputs and a modeled estimate to a primary care visit, an addiction medicine consult, or a counselor.
• • Compare drinking scenarios: Re-run the model with different drink counts, body weights, and elapsed times to see how each variable shifts the urine EtG reading.
• • Document the inputs and the result: Capture the model's assumptions and the inputs so a healthcare professional can interpret the modeled number in context.

EtG is a small, water-soluble byproduct that your liver makes when it processes ethanol. EtG stays in urine for a longer window than ethanol itself, so EtG is the marker most clinical and research laboratories use to assess drinking in the prior 24 to 80 hours.

A calculator cannot replace a lab test, but it can translate a drinking episode into a quantitative number and a number of hours, so the underlying pharmacokinetics is easier to discuss with a healthcare professional.

For the first few hours after drinking, the live intoxication estimate is more useful than the EtG metabolite estimate, so many people run both the BAC Calculator and this tool side by side.

The model estimates the post-drink urine EtG concentration in nanograms per milliliter, then decays it forward in time using a fitted single-compartment decay constant, so the same engine produces the live level, the time below 500 ng/mL, and the time to clear.

• drinks: Number of U.S. standard drinks consumed before the test window (1 drink = 14 g of pure alcohol per NIAAA)
• weight_kg: Body weight in kilograms, converted from pounds before any water-volume calculation
• r: Body water fraction: 0.68 for men, 0.55 for women, matching NIAAA's distribution assumptions
• t: Hours elapsed since the last drink was finished, used inside the exponential decay term
• 5.85: Empirical decay constant in hours for the single-compartment exponential model, fitted to typical urine EtG clearance curves in mainstream reference tools and aligned with the 500 ng/mL high cutoff in the SAMHSA 2006 advisory. Published pharmacokinetic studies describe EtG elimination in two phases (initial 2 to 3 hours, terminal 14 to 26 hours), which the single-compartment model collapses into one rate for planning use.

The two largest inputs are total drinks and body weight, because both alcohol mass and body water volume scale those numbers. Gender matters because women carry less body water per kilogram, so the same drinks spread across less volume and peak higher.

According to NIAAA, one U.S. standard drink contains about 14 grams of pure alcohol, the amount in 12 oz of 5% beer, 5 oz of 12% wine, or 1.5 oz of 40% distilled spirits

Four background ideas make the output easier to read; the calculator handles the math, but these definitions keep the numbers honest.

If you drink mixed cocktails with unknown pours, the Alcohol Units Calculator can turn ABV and volume into a clean standard-drink count before you enter it into the EtG calculator.

Use these six steps whenever you want a modeled EtG estimate for a known drinking episode at a specific elapsed time.

1. 1 Pick your gender: Choose male or female so the calculator can apply the correct body water fraction.
2. 2 Count your standard drinks: Add up the number of U.S. standard drinks you consumed in the recent drinking episode you want to model.
3. 3 Enter your body weight: Type your weight in pounds; the calculator converts to kilograms internally for the water volume math.
4. 4 Set the hours since the last drink: Use the planned time of the test, or the time that has already passed if you are checking a past result.
5. 5 Read the live EtG level: Look at the modeled urine EtG in ng/mL; values above 500 ng/mL sit on the high assay cutoff and values above 100 ng/mL sit on the low assay cutoff.
6. 6 Interpret the cutoff hours: Use the hours-below-cutoff outputs to discuss the modeled clearance window with a healthcare professional, a counselor, or a program coordinator, and pair the modeled estimate with a real assay whenever a clinical or legal decision depends on the number.

A 175 lb adult who drank 6 standard drinks at 9 pm and wants to understand the modeled urine EtG level 12 hours later, at 9 am, can enter drinks = 6, weight = 175, gender = male, hours = 12, and read both the current modeled EtG concentration and the time to the 500 ng/mL and 100 ng/mL thresholds. The result is a planning estimate, not a substitute for a laboratory EtG assay, so any clinical or program decision should be made with a healthcare professional.

If repeated heavy drinking is part of the picture, the Addiction Calculator can help frame the long-term health trade-offs alongside this short-term EtG estimate.

These six benefits focus on what a kinetic model actually adds to a learning or clinical workflow, not on outcomes that depend on a specific test result.

• • Translate pharmacokinetics into numbers: Convert a drinking episode into a quantitative urine EtG reading and a time-to-cutoff estimate, so alcohol metabolism and body water distribution are easier to discuss.
• • Visualize how body composition matters: See the same drinks produce a higher modeled peak in a smaller person or a woman of equal weight.
• • Explore the decay effect: Compare scenarios a few hours apart to see how the exponential decay moves the result from above 500 ng/mL toward the 100 ng/mL range.
• • Document the model's inputs: Keep a written record of drinks, body weight, and elapsed time that produced the estimate, so the result is reproducible.
• • Compare the 500 ng/mL and 100 ng/mL cutoffs: See both common assay thresholds in the same view, which makes the difference between a "high" and a "low" cutoff reading easier to interpret.
• • Frame the model's limits clearly: Treat the estimate as a kinetic planning aid, not a lab result, and pair it with a real assay whenever the number matters for a clinical or legal decision.

Five factors move the result up or down; the calculator captures the first three directly and flags the other two as caveats you should be aware of.

• • Single-exposure assumption. The calculator treats the input as one discrete episode, so a multi-day binge should be split into separate sessions or interpreted with extra caution.
• • Informational only. The estimate is a single-compartment kinetic model, not a clinical test, and SAMHSA has cautioned that EtG is "scientifically unsupportable as the sole basis for legal or disciplinary action" because the assay can detect incidental exposure.
• • Window outside the data. Heavy chronic use, very low body weight, or more than 96 hours of elapsed time push the calculator outside the calibration range.

According to MedlinePlus (NIH National Library of Medicine), urine drug tests can detect alcohol for hours to several days after use, and alcohol in products like mouthwash and hand sanitizer can produce a positive EtG result, which is why a positive screen is followed by a confirmatory test before action.

According to SAMHSA, the 500 ng/mL urine EtG cutoff is the high threshold commonly used in clinical and program settings, and the agency has cautioned that EtG alone is not a defensible basis for legal or disciplinary action

When the EtG estimate lines up with frequent recent drinking, the AUDIT-C Calculator can help you score the broader drinking pattern and decide whether to talk to a clinician.