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