Urine EtG Test Calculator
Specialized calculator for urine EtG detection with hydration and pH adjustments
Basic Parameters
Likely Negative
EtG level is likely below 100 ng/mL threshold
Current EtG: ~18 ng/mL
Recommendations:
- • Your EtG level is likely below the detection threshold.
- • Consider adding a 12-24 hour safety buffer before testing.
- • Avoid alcohol consumption until after your test.
- • This is an estimate - individual metabolism varies by ±20-30%.
Note: This calculator provides estimates based on scientific models. Individual results may vary by ±20-30% due to metabolism differences.
All calculations are performed locally in your browser. No data is sent to any server.
Interpreting Your Results
Negative (< 70% of cutoff)
EtG likely below threshold. Add 12-24h safety buffer before testing.
Borderline (70-120% of cutoff)
High-risk zone. Individual variation could affect results. Wait additional 24-48h if possible.
Positive (> 120% of cutoff)
Above threshold. Wait estimated clearance time plus 24h buffer. Retest as time passes.
Understanding Urine EtG Testing
Common Drinking Scenarios
Light (2-3 drinks)
Social drinking
Calculation Steps
- Peak: ~1,000 ng/mL
- Pass 500: 12-18h
- Pass 100: 24-36h
Moderate (5-6 drinks)
Evening out
Calculation Steps
- Peak: ~2,500 ng/mL
- Pass 500: 24-30h
- Pass 100: 48-60h
Heavy (10+ drinks)
Heavy session
Calculation Steps
- Peak: ~5,000 ng/mL
- Pass 500: 36-48h
- Pass 100: 72-96h
Binge (15+ drinks)
Excessive consumption
Calculation Steps
- Peak: ~8,000+ ng/mL
- Pass 500: 48-72h
- Pass 100: 96-120h+
Multi-Day
Consecutive days
Calculation Steps
- Peak: Varies
- Pass 500: 72h+
- Pass 100: 120h+
How to Use This Calculator
Enter Basic Information
Input drinks, weight, gender, and hours since last drink.
Adjust Urine Parameters
Select hydration level, urine pH, and kidney function in Advanced Parameters.
Select Detection Cutoff
Choose 100 or 500 ng/mL cutoff matching your testing program.
Review Results
Check EtG concentration, detection status, clearance time, and recommendations.
Save to History
Optionally save calculation to track changes (stored locally).
Why Use the Urine EtG Calculator?
Urine-Specific Accuracy
Accounts for hydration, pH, and kidney function - factors unique to urine testing that can change EtG concentration by 40%+. Critical for accurate estimates.
Longest Detection Window
24-80h detection window, significantly longer than blood (12-24h) or saliva (6-12h). Preferred for workplace/legal monitoring but requires careful timing.
Dual Threshold Support
Supports both 100 ng/mL (standard) and 500 ng/mL (high threshold) cutoffs to match your testing program requirements.
Personalized Recommendations
Tailored advice based on your hydration, detection status, and clearance time. Actionable recommendations, not just numbers.
Track Your Progress
Save calculation history to monitor EtG changes over time. Compare scenarios and track clearance progress. All data stays private in your browser.
Science-Based Transparency
Based on peer-reviewed research (Wurst et al., 2015; SAMHSA, 2012). Exact formulas, adjustment factors, and assumptions shown. Understand the ±20-30% variation range.
Understanding the Parameters
Hydration Level
Hydration status affects urine concentration. Dehydration concentrates EtG (higher readings), over-hydration dilutes it (lower readings).
Urine pH
Urine acidity/alkalinity affects EtG stability. Acidic (pH < 6) slightly increases stability, alkaline (pH > 7) may reduce it.
Kidney Function
Kidney's ability to filter EtG affects clearance rate. Impaired function extends elimination half-life.
Detection Cutoff
Testing facility threshold. 100 ng/mL is standard, 500 ng/mL is high threshold screening.
Urine EtG Calculation Formula
Scientific model with urine-specific adjustments
Peak Urine EtG Concentration
Estimates maximum EtG concentration. Gender factor: 12,000 (male), 14,000 (female), reflecting body water differences (Wurst et al., 2015).
Peak EtG = (Drinks × Gender Factor) / Body Weight (kg)
Example: 70kg male, 5 drinks: (5 × 12,000) / 70 = 857 ng/mL
Time-Adjusted EtG Concentration
Exponential decay model. Base half-life: 5h (SAMHSA, 2012). Kidney adjustment: normal (1.0×), mild impairment (1.15×), moderate (1.3×).
Current EtG = Peak EtG × 0.5^(Hours / Half-Life)
Example: After 24h, normal kidney: 857 × 0.5^(24/5) ≈ 30 ng/mL
Hydration Adjustment
Accounts for urine dilution. Factors: Dehydrated (1.3×), Normal (1.0×), Well-Hydrated (0.8×), Over-Hydrated (0.6×).
Adjusted EtG = Current EtG × Hydration Factor
Example: 30 ng/mL, well-hydrated: 30 × 0.8 = 24 ng/mL
pH Stability Adjustment
pH effects on stability. Factors: Acidic (1.05×), Neutral (1.0×), Alkaline (0.95×).
Final EtG = Adjusted EtG × pH Factor
Example: 24 ng/mL, neutral pH: 24 × 1.0 = 24 ng/mL
Clearance Time Estimation
Estimates hours to reach threshold using adjusted half-life.
Hours = Half-Life × log(Threshold / Current EtG) / log(0.5)
Example: 500→100 ng/mL, 5h half-life: 5 × log(100/500) / log(0.5) ≈ 11.6h
Frequently Asked Questions
EtG can be detected in urine for 24-80 hours after drinking, depending on the amount consumed, your metabolism, and testing sensitivity. Light drinking (2-3 drinks) typically clears in 24-36 hours, while heavy drinking (10+ drinks) may take 72-96 hours or longer.
EtG concentrates in urine as your kidneys filter it from your blood. While blood EtG typically clears in 12-24 hours, urine continues to accumulate EtG during this period, extending the detection window. This makes urine testing more sensitive but also more affected by hydration and kidney function.
100 ng/mL is the standard cutoff used by most programs and is more sensitive, detecting lower levels of alcohol consumption. 500 ng/mL is a higher threshold used for less sensitive screening. The 100 ng/mL cutoff can detect 1-2 drinks for up to 24-36 hours, while 500 ng/mL typically requires more significant drinking to trigger.
Yes, first morning urine is typically more concentrated because you haven't been drinking fluids overnight. This can result in higher EtG readings. If possible, provide a mid-day sample after normal hydration for more representative results.
Urine pH affects EtG stability. Acidic urine (pH < 6) slightly increases EtG stability and may result in marginally higher readings. Alkaline urine (pH > 7) may reduce stability slightly. However, the effect is relatively small (±5%) compared to hydration and metabolism factors.
Yes, impaired kidney function reduces the rate at which EtG is eliminated from your body, effectively extending the half-life. Mild impairment may extend clearance time by 15%, while moderate impairment could extend it by 30% or more. If you have kidney issues, consult with a healthcare provider.
This calculator is based on validated scientific models (Wurst et al., 2015; SAMHSA, 2012) and peer-reviewed research. However, individual metabolism varies by ±20-30% due to liver function, genetics, and overall health. Use estimates as a guide, not a guarantee. Always add a safety buffer before testing.
This calculator is for educational purposes only. It should not be used as the sole basis for legal, employment, or medical decisions. Results are estimates with inherent uncertainty. For high-stakes situations, consult with a healthcare professional, attorney, or testing facility.