Free Flight Connection Time calculator with clear step-by-step results.
A layover is not connection time. The clock starts when the aircraft door opens, not at the scheduled arrival, and it stops when boarding closes rather than at departure — so a 95-minute layover with a 20-minute boarding cutoff really offers 75 minutes. Subtract deplaning and terminal transfer, plus immigration and re-screening on an international-to-domestic connection, and add the delay you realistically expect on the inbound leg. What is left is the actual buffer.
Time consumed
Required = transfer + immigration and screening + boarding cutoff
Buffer
Buffer = (layover − expected inbound delay) − required
Minimum connection times, terminal layouts and border procedures differ by airport and itinerary. Verify with the airline and the airport before booking a tight connection, and treat this as planning guidance only.
Each airport publishes an MCT for each connection type, and airlines will not sell an itinerary below it — typically 30-45 minutes domestic-to-domestic and 60-90 minutes where you clear immigration and recheck bags. Meeting the MCT means the itinerary is legal, not that it is comfortable.
On a single ticket the airline is obliged to rebook you, and duty-of-care rules may apply. On two separate tickets you have no such protection and would normally have to buy a new fare, which is why self-transfers need a much larger buffer.
No, but you are relying on things going better than planned. Treat a negative result as a prompt to pick a later onward flight, or to accept the risk knowingly.