EtG Calculator
Hours since your last drink and a cutoff of 100, 250, 500 or 1,000 ng/mL give published EtG urine detection rates. It does not predict a result. How it works
Use the EtG Calculator
About the EtG Calculator
At the 500 ng/mL cutoff most commercial labs use, one study detected heavy drinking in 78% of urine samples one day after the last drink and in under 71% at two to five days. At 100 ng/mL it detected heavy drinking in 84% at one day and 79% at five days (McDonell 2015). The page shows those published figures for the hours and cutoff you enter; it cannot tell you whether your own EtG test will be positive.
What the studies found at each cutoff
| Cutoff | Detected one day after the last drink | Detected at five days | False positives |
|---|---|---|---|
| 100 ng/mL | Light drinking 85%, heavy 84% | Light drinking 66%, heavy 79% | 29% with a previous-day window, 16% with a five-day window |
| 250 ng/mL | Not reported | Not reported | Not reported |
| 500 ng/mL | Heavy drinking 78% | Heavy drinking under 71% (two to five days) | 3% over five days |
| 1,000 ng/mL | Not reported | Not reported | Not reported |
McDonell et al. 2015, samples from outpatients in alcohol treatment. A false positive was a positive sample with no drinking reported in the window; the shorter the window, the more samples count as false positives, which is why the 100 ng/mL figure is higher at one day. The study also gives 6% at 200 ng/mL over five days.
SAMHSA urine EtG bands
| Result | May indicate |
|---|---|
| 100 to 500 ng/mL | Previous heavy drinking (1 to 3 days); Previous light drinking (12 to 36 hours); Recent "extraneous" exposure (for example hand sanitizer) |
| 500 to 1,000 ng/mL | Previous heavy drinking (previous 1 to 3 days); Recent light drinking (for example the past 24 hours); Recent intense "extraneous" exposure (within 24 hours or less) |
| Above 1,000 ng/mL | Heavy drinking on the same day or previously (for example the previous day or two); Light drinking the same day |
SAMHSA advisory on biomarkers in the treatment of alcohol use disorders (2012 revision), as reproduced in Clinical and Forensic Toxicology News (ADLM, September 2022).
Frequently asked questions
- How long does EtG stay in urine?
- The studies the page cites followed drinkers for up to 120 hours (five days). At a 100 ng/mL cutoff heavy drinking was still detected in 79% of samples at five days; at 500 ng/mL detection of heavy drinking fell under 71% after the first day. Detection depends on how much was drunk, the person, the sample and kidney function, so no fixed number of hours is given.
- What does a 500 ng/mL EtG cutoff mean?
- It is the concentration above which a lab reports the sample as positive. Lowe 2015 calls 500 ng/mL the cutoff used by most commercial laboratories; labs use anything from 100 to 1,000 ng/mL. In the SAMHSA bands a result of 500 to 1,000 ng/mL may indicate heavy drinking in the previous 1 to 3 days, light drinking in the past 24 hours, or recent intense exposure to products that contain alcohol.
- Can hand sanitizer or mouthwash cause a positive EtG test?
- They can produce detectable EtG, as can small amounts in soy sauce, non-alcoholic beer and wine, sauerkraut and ripe bananas. In the SAMHSA bands, recent exposure of this kind is one reading of a result of 100 to 500 ng/mL, and recent intense exposure within about 24 hours one reading of 500 to 1,000 ng/mL. That is why many laboratories use the higher cutoff.
- How common are false positives on an EtG test?
- In McDonell 2015, a positive sample from someone who reported no drinking in the previous five days happened in 16% of samples at 100 ng/mL, 6% at 200 ng/mL and 3% at 500 ng/mL. When the look-back window was only the previous day, the 100 ng/mL figure was 29%. Participants had been advised to avoid non-beverage sources of ethanol, so these rates are not a measure of products such as hand sanitizer or mouthwash.
- Can this calculator tell me if I will pass an EtG test?
- No. It has no inputs for drinks or body weight and does not estimate an EtG level. It shows what studies of groups of treatment patients found, which says nothing certain about one person. Do not use it for a legal, medical or employment decision.
- What do EtG levels of 100, 500 and 1,000 ng/mL mean?
- In the SAMHSA bands, 100 to 500 ng/mL may indicate heavy drinking 1 to 3 days before, light drinking 12 to 36 hours before, or recent exposure to products such as hand sanitizer. 500 to 1,000 ng/mL may indicate heavy drinking in the previous 1 to 3 days, light drinking in the past 24 hours, or recent intense exposure within 24 hours or less. Above 1,000 ng/mL may indicate heavy drinking the same day or the previous day or two, or light drinking the same day.
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