Whether one beer puts you over the legal driving limit depends on the beer's size and ABV, your body weight and biological sex, and your country's limit. A 330 mL beer at 5% ABV (~13 g ethanol) typically produces a BAC of: ~0.022% in an 80 kg male, ~0.030% in a 60 kg female. That single beer already exceeds Sweden's 0.02% limit and gets close to Norway's 0.02%. It is well below the US/UK limit of 0.08% and most European 0.05% limits — but impairment begins below the legal limit. Research from the NHTSA shows measurable reaction-time and tracking impairment at BAC as low as 0.02%. The safest answer for any driver is to wait until BAC returns to zero. For a single 330 mL 5% beer, that takes about 60 to 90 minutes after the last sip for most adults — slower for women and lower-weight individuals. Use the AlcoInsights Time to Sober calculator to estimate your personal clearance time and the BAC Calculator to model multiple-drink scenarios. Sources: NHTSA "Alcohol-Impaired Driving," NIAAA, WHO Global Status Report on Road Safety.