How Much Layover Time Do You Need for a Connecting Flight?

Book at least 60 to 90 minutes between connecting flights — the technical domestic minimum some airlines allow is often just 30 minutes, which isn't a safety margin. Add 30 to 60 more minutes at a large hub or a two-airline itinerary, and check your specific inbound flight's history: late-arriving aircraft cause roughly 39% of US flight delay-minutes, per US DOT data.

• Minimum Connection Time (MCT) — commonly 30 to 45 minutes domestic, 60 to 90+ minutes international — is the legal floor airports and airlines set, not a comfortable margin.
• Aim for 60 to 90 minutes on a same-airline domestic connection, and 90 to 120+ minutes when your itinerary splits across two separate airlines.
• Late-arriving aircraft cause about 39% of US flight delay-minutes — more than weather or air traffic control — so a tight layover is really a bet that your first flight leaves on time.
• Not every hub is equally risky: Portland (PDX) and Salt Lake City (SLC) depart on time around 84% of the time; Dallas/Fort Worth (DFW) is closer to 72%, so the same layover is a different bet depending on where it happens.
• Check your specific flight, not just a rule of thumb — look up your inbound flight number's own on-time history before you decide a tight connection is safe.

What is Minimum Connection Time (MCT)?

Minimum Connection Time (MCT) is the shortest layover an airline or airport will sell as a legal connection between two flights on the same ticket. It's set by the airport authority and the airlines operating there, based on typical gate distances and how fast security or immigration lines usually move. In the US, domestic MCT is commonly 30 to 45 minutes; international connections — which add a pass through immigration and customs, and sometimes a second security screening — are commonly 60 to 90 minutes or more. Airlines will sell you a connection at exactly the published MCT. That makes it bookable, not comfortable.

How much layover time should you actually book?

Treat MCT as a floor, not a target. A widely used travel-industry rule of thumb is 60 to 90 minutes for a domestic connection and at least 2 to 3 hours for an international one, with more added at busy hub airports. How much you actually need depends on a few factors:

• Same airline, one ticket, domestic to domestic: 60–90 minutes is usually enough, especially with no checked bag.
• Different airlines or separate tickets: budget 90–120 minutes or more. If your first flight runs late, the second airline has no obligation to hold the flight or rebook you for free.
• International connections: 2–3 hours, to cover immigration, customs, and a possible second security screening.
• Large or unfamiliar hub airports: add 30–45 minutes on top of the above for a longer walk, an inter-terminal train, or a layout you don't know.
• Checked bags on a tight connection: add extra margin — your bag has to physically make the transfer too, and it moves slower than you do.

Why late-arriving aircraft make a tight layover risky

Layover math usually assumes your inbound flight leaves and lands on time. That's a bigger assumption than it sounds like. Late-arriving aircraft — a plane that's late for your flight because it arrived late from somewhere else — is the single biggest cause of US flight delays, responsible for roughly 39% of all delay-minutes across 14.1 million US flights from June 2024 through May 2026, more than weather, air traffic control, or the airline's own operations at your departure airport. That domino effect builds through the day, which is exactly why a generic 90-minute cushion isn't really 90 minutes if your first flight already departed 45 minutes behind schedule.

Check your specific flight and airport before you book

A generic rule of thumb treats every layover the same, but real flights aren't identical. Before locking in a tight connection, check two things instead of guessing. First, look up your inbound flight's own on-time history — every flight number tracked on FlightRecord has a dedicated page (Delta 423, for example, lives at flightrecord.app/flights/dl-423) showing how consistently it actually runs on schedule. A flight that's chronically running late needs a bigger buffer than the printed schedule suggests.

Second, factor in the connecting airport itself. Some hubs run consistently better than others: Portland (PDX) and Salt Lake City (SLC) both depart on time around 84% of the time, while Dallas/Fort Worth (DFW) is closer to 72% — so the same 75-minute layover is a very different bet depending on where it happens. It's worth checking your specific route the same way; a route like JFK to LAX can be looked up directly for its own on-time record rather than assumed from the airport average.

For the full airport-by-airport comparison — which hubs handle a tight connection best, and which ones deserve extra buffer — see which US airports are best for connecting flights.

Frequently asked questions

What is the minimum legal layover time for a connecting flight?

There's no single federal minimum — it's set by each airline and airport as their Minimum Connection Time (MCT), commonly 30 to 45 minutes for domestic-to-domestic connections and 60 to 90 minutes or more for international ones. Airlines won't sell a connection shorter than their published MCT, but meeting it doesn't guarantee you'll make the flight if your inbound leg runs late.

Is a 45-minute layover enough?

It can work for a same-airline, domestic, no-bag connection at an airport you know, especially if both flights use the same terminal. It's tight if you're checking a bag, changing terminals, connecting between two different airlines, or arriving at a large hub you've never navigated — in those cases, aim for 60 to 90 minutes instead.

How much layover time do I need for an international connection?

Plan for at least 2 to 3 hours. International connections typically require clearing immigration and customs, and sometimes a second pass through security, on top of the standard walk between gates.

Does it matter if my connecting flights are on two different airlines?

Yes. When both legs are on one ticket with one airline or its codeshare partners, that airline is generally responsible for rebooking you if you misconnect because of a delay it caused. Separate tickets on separate airlines don't come with that protection, so a longer buffer — 90 minutes or more domestically — is worth the trade-off against a slightly cheaper fare.

How can I tell if my specific connection is risky before booking?

Look up your inbound flight number's on-time history and the connecting airport's overall reliability rather than relying on a generic layover rule. A flight or airport with a track record of running late needs more buffer than the minimum connection time suggests.