Alcohol Unit Calculator & AUD Pathway

Volumetric Conversion, AUDIT-C & Risk Stratification (Indian Context) · v1

How to use this tool: Quantify intake using standard Indian measures, complete the AUDIT-C, and record the clinical indicators of dependence. The tool returns a diagnostic formulation.

If the patient has already stopped drinking, this is not the right tool. This one quantifies intake and screens for a use disorder. For a patient who is withdrawing, or who is about to, use the Alcohol Withdrawal: CIWA-Ar and Thiamine Protocol, which scores severity, selects a benzodiazepine regimen and generates the thiamine protocol.

1. Patient Demographics

Biological Sex ?

2. Volumetric Intake (Typical Drinking Day)

Beverage Type ?

Standard Measure ?

Quantity per session

Frequency (Days/Week)

3. AUDIT-C Rapid Screen

How often do you have a drink?

Typical drinks on a drinking day?

How often do you have 6+ drinks on one occasion?

4. Clinical Flags (Dependence & Harm)

Morning tremors, sweating, or needing an "Eye-Opener" Loss of control over intake or profound tolerance Evidence of organ damage (e.g., deranged LFTs, macrocytosis) Significant social, occupational, or familial impairment

Quantitative Intake Analysis

Total Weekly Units

0Units/week

AUDIT-C Score

0/ 12

Educational Pearl: The Medical Unit
One standard UK medical unit equals 10 ml (8 g) of pure ethanol. The safe threshold is ≤ 14 units per week for both men and women. Indian patients often dramatically underestimate their intake because standard Indian spirits (IMFL) are strong (42.8%) and served in large volumes (e.g., a 60 ml "large peg" is over 2.5 units).

Clinical Formulation

Diagnostic Stratification

Low Risk

Clinical Insight: Diagnosis vs. Pathology
Hazardous drinking increases the future risk of harm. Harmful drinking means end-organ or psychological damage is currently active. Dependence implies a physiological reliance (tolerance/withdrawal). Do not recommend abrupt cessation in dependent patients due to the high risk of seizures or delirium tremens; plan a medically supervised withdrawal.

Patient-Friendly Summary

1. What is a Unit?

A "unit" of alcohol is a standard medical measure used to quantify the mass of pure ethanol within a beverage. It allows clinicians to track consumption uniformly regardless of the beverage type.

Standard Definition: 1 Unit = 10 millilitres (ml) or 8 grams of pure ethanol.
The Formula: Units = (Volume in ml × ABV %) / 1000
Safe Limits: Current guidelines recommend consuming ≤ 14 units per week, spread evenly over 3 or more days, with multiple alcohol-free days.

2. Volumetrics & The Indian Context

Indian drinking patterns often involve spirits with higher ABV and larger standard pours than Western textbooks describe. Misunderstanding these sizes leads to severe underestimation of patient risk.

Indian Beverage & Measure	ABV (%)	Approx. Medical Units
IMFL (Whisky/Rum/Vodka) - Large Peg (60 ml)	42.8%	2.6 Units (Nearly 1/5th of the weekly limit)
IMFL - "Quarter" / Pauwa (180 ml)	42.8%	7.7 Units (A heavy binge dose)
Strong Beer - Standard Bottle (650 ml)	8.0%	5.2 Units
Standard Beer/Lager - Pint (330 ml)	5.0%	1.7 Units
Country Liquor / Arrack (100 ml)	~35.0%	3.5 Units (Variable; high risk of contaminants)

3. The AUDIT-C Screening Tool

The AUDIT-C is a rapid 3-question screen validated for identifying active AUD or hazardous drinking.

Score Range: 0 to 12.
Sex-Specific Cutoffs: A score of ≥ 4 in men or ≥ 3 in women is considered a positive screen.
Clinical Utility: Highly sensitive for primary care. A positive AUDIT-C mandates a full 10-question AUDIT assessment and physical examination.

Practice Pearl: The sex-specific cutoff is routinely ignored in Indian clinical practice. A female patient scoring 3 on the AUDIT-C is positive and requires full evaluation, yet many clinicians apply the male cutoff of 4 universally, missing hazardous drinking in women.

4. Mnemonic: Recognising Dependence (CRAVE)

The word itself describes the disease. Use CRAVE to rapidly assess for core features of alcohol dependence at the bedside:

Letter	Feature	Bedside Clue
C	Compulsion	Strong, persistent craving or urge to drink
R	Relapse	Repeated failed attempts to cut down
A	Autonomic withdrawal	Morning tremors, sweating, "eye-openers"
V	Volume tolerance	Needs markedly more to feel the same effect
E	Erosion of function	Social, occupational, or familial breakdown

Two or more features, especially A and V together, indicate probable dependence (severe AUD per DSM-5).

5. Decoding Clinical Flags

1. A. Physiological Dependence (Withdrawal & Tolerance)

Tolerance: The need for markedly increased amounts of alcohol to achieve intoxication, or a markedly diminished effect with continued use of the same amount. This indicates CNS (GABA/NMDA) receptor adaptation.

Withdrawal ("Eye-Openers"): Autonomic hyperactivity (sweating, tachycardia, hand tremor) upon waking, relieved by consuming alcohol. This is a critical red flag for severe AUD. Never advise abrupt cessation; these patients require a tapered benzodiazepine protocol (e.g., CIWA-Ar) to prevent seizures and DT.

2. B. Harmful Drinking (Organ Damage)

Evidence that alcohol is actively causing physical pathology. Look for:
• Biochemical Pearl (The De Ritis Ratio): In alcoholic liver disease, AST is typically elevated disproportionately to ALT. An AST:ALT ratio of > 2:1 strongly suggests alcohol aetiology. This occurs due to alcohol-induced mitochondrial damage and a relative deficiency in pyridoxal-5'-phosphate (the active form of Vitamin B6).
• Macrocytosis: Elevated MCV due to direct bone marrow toxicity, often independent of B12/Folate deficiency. An MCV > 100 fL in a drinker should trigger a frank conversation even if the patient denies excessive intake.

6. Illness Script: Differentiating Liver Disease Aetiologies

Feature	ALD	NAFLD/MASLD	Viral Hepatitis (B/C)
Key History	Sustained heavy drinking (>14 U/wk)	Metabolic syndrome, obesity, T2DM	Transfusion, IVDU, endemic region, vertical transmission
AST:ALT Ratio	> 2:1 (classic)	< 1:1 (ALT usually higher)	Variable; ALT often dominant
GGT	Markedly elevated (often >3x ULN)	Mildly elevated	Variable
MCV	Elevated (> 100 fL)	Usually normal	Usually normal
Confirmatory Test	History + CDT + exclusion	FibroScan, USS, FIB-4	HBsAg, Anti-HCV, viral load

3. Indian Clinical Guidelines & Preventable Errors

The "Glucose First" Error: Administering IV Dextrose to a hypoglycaemic or malnourished alcoholic patient without prior IV Thiamine. Glucose metabolism rapidly consumes the remaining cellular thiamine, precipitating acute, irreversible Wernicke-Korsakoff syndrome. Always give IV Thiamine (Pabrinex) first, then Dextrose.

Inadequate Withdrawal Protocols: Discharging a dependent patient with a few tablets of oral chlordiazepoxide "SOS" for sleep or tremors is clinically insufficient. AWS requires a structured, objective severity assessment (CIWA-Ar) and a dedicated tapering schedule to prevent late-onset DT, which can manifest 48 to 72 hours after the last drink.

Overlooking Thiamine Deficiency: In Indian government hospitals, IV thiamine is often unavailable. If injectable thiamine is not stocked, oral thiamine (100 mg TDS) must be started immediately and IV form must be procured urgently for any patient with suspected Wernicke encephalopathy (confusion, ataxia, ophthalmoplegia). The triad is present in only 16% of cases; a high index of suspicion is essential.

Abbreviations: ABV (Alcohol by Volume) · ADH (Alcohol Dehydrogenase) · ALD (Alcoholic Liver Disease) · ALT (Alanine Aminotransferase) · Anti-HCV (Antibody to Hepatitis C Virus) · AST (Aspartate Aminotransferase) · AUD (Alcohol Use Disorder) · AUDIT (Alcohol Use Disorders Identification Test) · AUDIT-C (Alcohol Use Disorders Identification Test - Consumption) · AWS (Alcohol Withdrawal Syndrome) · CDT (Carbohydrate-Deficient Transferrin) · CIWA-Ar (Clinical Institute Withdrawal Assessment for Alcohol, revised) · CNS (Central Nervous System) · DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition) · DT (Delirium Tremens) · FIB-4 (Fibrosis-4 Index) · GABA (Gamma-Aminobutyric Acid) · GGT (Gamma-Glutamyl Transferase) · HBsAg (Hepatitis B Surface Antigen) · IMFL (Indian Made Foreign Liquor) · IV (Intravenous) · IVDU (Intravenous Drug Use) · LFT (Liver Function Test) · MASLD (Metabolic Dysfunction-Associated Steatotic Liver Disease) · MCV (Mean Corpuscular Volume) · NAFLD (Non-Alcoholic Fatty Liver Disease) · NMDA (N-methyl-D-aspartate) · PAWSS (Prediction of Alcohol Withdrawal Severity Scale) · SOS (Si Opus Sit, If Required) · T2DM (Type 2 Diabetes Mellitus) · TDS (Three Times Daily) · ULN (Upper Limit of Normal) · USS (Ultrasonography)

Algorithm References & Evidence Base

Bush K, Kivlahan DR, McDonell MB, Fihn SD, Bradley KA. The AUDIT alcohol consumption questions (AUDIT-C): an effective brief screening test for problem drinking. Arch Intern Med. 1998;158(16):1789-1795.
Bradley KA, DeBenedetti AF, Volk RJ, Williams EC, Frank D, Kivlahan DR. AUDIT-C as a brief screen for alcohol misuse in primary care. Alcohol Clin Exp Res. 2007;31(7):1208-1217.
Indian Council of Medical Research (ICMR). Standard Treatment Workflows (STW) - Management of Alcohol Use Disorders. New Delhi, India; 2022.
Association of Physicians of India (API). API Textbook of Medicine, 13th Edition. Chapter: Disorders related to substance use; 2022.
National Institute of Mental Health and Neuro-Sciences (NIMHANS). Clinical Practice Guidelines for the Management of Substance Use Disorders. Bengaluru, India; 2016.
World Health Organization. Global status report on alcohol and health 2018. Geneva: WHO; 2018.

How to Cite This Tool

AMA Style:
Umakanth S. Alcohol Unit Calculator & AUD Pathway. MEDiscuss. Published 2026. Accessed .

Vancouver Style:
Umakanth S. Alcohol Unit Calculator & AUD Pathway [Internet]. MEDiscuss.org; 2026 [cited ]. Available from:

Category Risk Scores & Diagnostic PathwaysPathway

Specialties Internal Medicine, Gastroenterology & Hepatology, Toxicology, Psychiatry

Written and maintained by Dr Shashikiran Umakanth.
Last revised: 29 July 2026

Back to All Medical Calculators & Pathways