Connection Planner
Fill this in when you book, not at the airport. The spare figure is the one to remember - it is how late your inbound can be before the connection breaks.
BFCBrilliance · bfcbrilliance.com/tools/flight-time-and-layover-calculator
The connection
- Date
- Connecting airport
- Inbound flight number
- Inbound lands (local)
- Outbound flight number
- Outbound departs (local)
- LAYOVER
- Airline's minimum connection time
- Extra ground time needed
- SPARE
What eats the spare
- Immigration and passport control on arrival
- Collecting checked bags and re-checking them
- Changing terminal - check whether it needs a train or a bus
- Clearing security a second time
- A gate at the far end of a long pier
- Waiting for a remote stand and a bus to the terminal
- Deplaning from a rear seat on a full wide-body
- Any of the above at an airport you have never used
The arithmetic
- Layover
- outbound departs − inbound lands
- Ground time needed
- airline minimum + your extra
- SPARE
- layover − ground time needed
- Spare also equals
- how late the inbound can be
- Negative spare
- the connection is broken, not tight
- Overnight connection
- add 24 h before subtracting
Where to get the minimum connection time
- The authority
- your airline, or the airport's own site
- It varies by
- terminal, airline, domestic vs international
- One ticket
- the airline applied its own figure to sell it
- ⚠ Separate tickets
- NO minimum applies - it is all yours
- ⚠ This tool
- does not guess it, on purpose
Separate tickets change everything
A minimum connection time is a rule an airline applies to its own itineraries. On two separate tickets nothing protects you: a missed connection is your cost, the second airline owes you nothing, and you will usually have to collect and re-check bags. Budget the spare as money you are personally risking rather than a margin someone else is standing behind.
The spare is the number to carry
Not the layover. A 95-minute layover with a 60-minute minimum leaves 35 minutes of spare - so a 40-minute inbound delay breaks it, even though 95 minutes sounded comfortable when you booked. Write the spare on your itinerary, and check it against the inbound's actual arrival while you are still in the air.