Layover Time Calculator
Check if your layover is long enough for a connection, customs, or a city visit.
Returns minimum times by airport for domestic and international flights.
Layover time planning is the difference between a smooth connection and a missed flight. This calculator factors in arrival time, terminal distance, customs clearance, and gate availability to assess whether your connection is safe.
Minimum connection time (MCT) formula:
Available Connection Time = Layover Duration − Buffer Risks
Buffer Risks = Arrival Delay Risk + Terminal Change Time + Customs Time + Walk/Transit Time + Security Re-entry Time
Minimum safe layover times by scenario:
| Scenario | Minimum Recommended |
|---|---|
| Domestic-to-domestic, same terminal | 45–60 minutes |
| Domestic-to-domestic, different terminal | 60–90 minutes |
| International arrival, domestic connection | 90–120 minutes |
| International-to-international | 60–90 minutes |
| US Customs + re-security required | 120–180 minutes |
| First flight on separate booking | Add 60 min buffer |
Worked example: Flight arrives 2:15 PM. Connecting flight departs 4:10 PM. Available time: 115 minutes.
- International arrival → US connection: need immigration + customs + re-check bag + security
- Buffer needed: ~120 minutes
- Risk assessment: Borderline, book a backup if possible
Red flags that increase miss risk:
- First flight frequently delayed (check FlightAware stats)
- Weather-sensitive departure city (Chicago, Denver, Dallas in winter)
- Separate airline bookings (you bear the rebooking cost)
- Busy hub airports with long walks (DFW, LAX, JFK Terminal changes)
Rule of thumb by airport size:
- Small regional airport: 30 min often fine for domestic
- Medium hub (Boston, Seattle): 60–75 min domestic
- Large hub (LAX, JFK, ORD): 90–120 min domestic; 3+ hours international
How we build and check this calculator
This calculator runs entirely in your browser, so the numbers you enter stay on your device. The math behind it is written by hand and tested against worked examples and standard references before the page goes live.
SuperGlobalCalculator is independently built and maintained. See how we build and verify our calculators.