How Much Layover Time Do You Actually Need?

When a booking site shows a 35-minute connection, it isn’t guessing — it’s selling you a layover that clears the airport’s minimum connection time (MCT). But MCT is a legal floor, not a comfortable buffer. The real question is how much margin you have above it.

What minimum connection time really means

Every airport publishes an MCT — the shortest gap an airline is allowed to sell between an arriving and a departing flight — and it differs for domestic vs. international connections, because international transfers can add immigration, customs, and a bag recheck. A booking engine won’t sell you a connection below MCT, but it will happily sell you one right at it. Land a few minutes late and that connection is gone.

What eats your buffer

• An inbound delay — the single biggest factor, and the one you can’t see when you book.
• Gate distance — a different terminal or concourse can be a 15–20 minute walk or a train ride.
• Immigration & customs on international arrivals, plus re-clearing security.
• Bag recheck if your luggage isn’t checked through.
• Deplaning — simply getting off a full widebody eats 10–15 minutes.

A practical rule of thumb

At a major hub, aim well above the legal minimum:

• Domestic: 60–90 minutes is comfortable; under ~45 is tight.
• International (or any customs): 90–120+ minutes.
• Add more for big/complex hubs, winter weather, or if it’s the last flight of the day — miss it and you’re overnighting.

One ticket vs. two

If your whole trip is on a single ticket and you misconnect, the airline must rebook you on the next available flight at no charge. If you booked the legs as separate tickets to save money, a missed connection is entirely your problem — the second airline owes you nothing. That cheap self-transfer can become the most expensive part of the trip. If it does go wrong, here’s what to do the moment you misconnect.