How long should a layover be for an international flight?

Arriving in the U.S. from abroad, you clear immigration and customs, collect and recheck your bags and go through TSA again, so plan on two hours or more; Global Entry and PreCheck cut that noticeably. Connecting abroad, allow time for transfer security and any passport control.

Do I have to go through customs on a connecting flight to the U.S.?

Yes, at your first U.S. airport, even if your final destination is another U.S. city. The exception is preclearance: at airports such as Toronto, Vancouver, Montreal, Dublin and Abu Dhabi you clear U.S. customs before you board and land as a domestic passenger.

What happens if I miss my connection?

If both flights are on one ticket, the airline rebooks you on the next available flight at no charge. On separate tickets, the second airline treats you as a no-show, so leave much more time or buy one ticket.

What's a self-transfer?

Connecting between flights booked on separate tickets. You collect your bags, check in again and clear security, with no protection if the first flight is late. Our calculator adds this time when you choose separate tickets.

Layover calculator · 56 airports

Is your layover long enough?

Pick your connecting airport and answer a few questions. We add up every step, from the walk off the plane to customs, bag recheck and security, and show you exactly where the time goes.

Verified Oct 17, 2026By Steven MoHow we check Report a correction

How long a layover do I need?

Connecting airport

Are you changing terminals?

At ATL you switch by Plane Train.

Is your first flight arriving from another country?

You'll clear immigration and customs here.

Do you have checked bags?

Are your flights on separate tickets?

If so, the airline won't rebook you if you miss it.

Do you have Global Entry and TSA PreCheck?

Recommended minimum

55 min

Comfortable: 1 h 30 min

Get off the plane and walk to your next gate25 min
Be at the gate before boarding closes15 min
Buffer for a small delay15 min

Our estimate, rounded up, not the airline's official minimum connection time. If both flights are on one ticket, the airline will rebook you if a delay makes you miss the second one. How we calculate this

Atlanta (ATL) connection guide

Minimum connection time vs. the time you actually need

Airlines file an official minimum connection time (MCT) for each airport and won't sell a connection shorter than that. It's the least time a connection can take when everything runs on schedule, which is why a 40-minute layover can be perfectly "legal" and still stressful.

Our recommendations add the steps that really happen at each airport, including terminal changes, re-screening, customs and bag recheck, plus a small buffer for delays. If both flights are on one ticket and you misconnect, the airline will rebook you. On separate tickets, you're on your own.

U.S. airports

Recommended minimum for a domestic connection, and after an international arrival.

International hubs

Recommended minimum for a same-terminal connection.

Layover FAQ

For a domestic connection on one ticket, usually yes at single-terminal airports and hubs where every terminal is linked inside security; we recommend about 45 min–55 min. It's not enough after an international arrival into the U.S., which takes about 2 h 25 min at Atlanta, or for a terminal change that means going through security again.

Sources

Last verified Oct 17, 2026. Each airport page lists the sources for that airport. Terminals change, so check your airline's connection instructions before a tight layover.

Read how we collect and check this data, or tell us if something's out of date.

From our researchConnection Time Index 2026Every airport ranked by how long a connection really takes after customs or a terminal change.Read the study

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