How much time you really need for a connection

What MCT is and why it varies from airport to airport

The minimum connection time, indicated by the acronym MCT in booking systems, depends on the distance between gates and the efficiency of each hub's internal controls. At Frankfurt an international-to-international connection may require as little as 45 minutes, while at London Heathrow the same type of connection reaches 75-90 minutes; at Singapore Changi it typically falls between 50 and 60 minutes.

The type of connection changes the calculation

A domestic-to-domestic connection generally requires less time than one that goes from an international area to a domestic one, where a new passport control is added. The terminal change also matters: some airports require a shuttle or internal train, a time that must be added to what is already planned for controls and verified separately.

Why a margin just above the minimum remains risky

Booking systems generally do not sell connections below the published minimum time, but that figure describes ideal conditions: no delays, no queues, no distant gates. Adding a margin of 30-60 minutes beyond the official MCT, especially during peak traffic periods when queues at controls get longer, is the buffer that really reduces risk.

Before accepting a connection close to the published minimum, check the specific MCT for that airport on the airport's website or with your airline's app, and mentally add half an hour of margin.