Every country publishes its own figures, so precise numbers have to come from the destination's customs website, but the template is consistent worldwide. Alcohol allowances are set per adult and split by strength: a liter or so of spirits is a common ceiling, wine gets a somewhat larger volume, and beer more still, with some countries offering a choose-one-or-mix formula. Tobacco follows the same logic, a fixed count of cigarettes, often a couple of hundred or fewer, with equivalents for cigars and loose tobacco, and the totals keep shrinking as health policy tightens.
Surrounding conditions matter as much as the numbers: allowances apply only to travelers above the legal age, usually cannot be pooled with companions, include what you bought on board the flight, and in some regions differ depending on whether you arrive from inside or outside a customs union. Dry jurisdictions ban alcohol entirely.
If you land over the limit, declare and pay duty on the excess; concealment converts a minor cost into seizure and fines.