EtG Calculator

What Is EtG on a Drug Test?

Ethyl glucuronide (EtG) is a direct metabolite your liver produces when it breaks down ethanol. Unlike a breathalyzer, an EtG urine test does not measure current intoxication. It looks for this metabolite to estimate recent alcohol exposure over the prior one to five days. For current blood alcohol, use the BAC Calculator.

How the EtG Estimate Works

This tool models EtG using standard U.S. drink sizes (14 g ethanol per drink), body water distribution by gender, and exponential decay after the last drink. The formula follows the mainstream kinetic model used in clinical education tools:

$$EtG(t) = \frac{\text{drinks} \times 14 \times 1066}{\text{weight}_{kg} \times r} \times 0.5^{t / 5.85}$$

Where $r$ is 0.68 for men and 0.55 for women, and $t$ is hours since the last drink finished.

Realistic EtG Detection Windows

Detection time depends on how much you drank, body weight, and biology. Typical ranges reported in addiction medicine references include:

• Light drinking: often 24 to 36 hours
• Moderate drinking: about 48 to 72 hours
• Heavy drinking: up to five days in some cases

Many programs use a 500 ng/mL high cutoff. A more sensitive 100 ng/mL cutoff can detect lighter exposure but also raises false-positive risk from incidental sources such as mouthwash.

Using This Calculator

1. Select gender for the Widmark body water factor.
2. Enter the number of U.S. standard drinks consumed.
3. Enter body weight and hours elapsed since your last drink.
4. Review the modeled EtG level and estimated hours to common cutoffs.

If you are reducing alcohol use, the CIWA Calculator can help score withdrawal symptoms during supervised care.