There is no universal "number" of drinks you are legally allowed to have on a plane, but the limit is governed by FAA regulations (and international equivalents) which strictly prohibit airlines from serving alcohol to anyone who appears to be intoxicated. In 2026, flight attendants are trained to monitor passengers closely; if they believe you are becoming a safety risk or disruptive, they will cut you off immediately. Additionally, it is a federal crime to consume your own alcohol (purchased at duty-free or brought from home) on board an aircraft; only alcohol served by the crew can be consumed. While some 2026 international baggage rules allow you to carry up to 2 liters of alcohol duty-free through customs, once you are in the air, your consumption is entirely at the discretion of the cabin crew's safety assessment.