A "standard drink" is a unit defined by how many grams of pure ethanol it contains. Definitions vary by country: United States 14 g, Canada 13.6 g, Sweden 12 g, Denmark 12 g, United Kingdom 8 g (one "unit"), Australia 10 g, France 10 g. Converting your actual drink to standard drinks is simple: alcohol grams = volume (mL) × ABV (%) × 0.789 / 100, then divide by your country's standard-drink size. Common examples: a 355 mL US beer at 5% ABV ≈ 14 g ethanol = 1 US standard drink, 1.75 UK units, 1.17 Swedish standard glass. A 175 mL glass of 13% wine ≈ 18 g ethanol = ~1.3 US drinks, ~2.2 UK units. A 44 mL shot of 40% spirits ≈ 14 g ethanol = 1 US standard drink. NIAAA defines low-risk drinking as ≤ 14 standard drinks/week for men and ≤ 7 for women; the UK CMO guideline is ≤ 14 units/week for both sexes. Sources: NIAAA "What's a Standard Drink?", UK NHS alcohol units guidance, Folkhälsomyndigheten (Sweden).