Airport gate intelligence · SEA
How many gates does Seattle Airport (SEA) have?
Seattle Airport (SEA) has 97 gates, with about 581 airline departures a day. Alaska has the most (44), followed by Delta (19).
Alaska flies 54% of the 83,569 seats leaving SEA each day. Alaska has 132% more gates and 100% more seats than Delta. 19 gates are common use, shared by several airlines.
Gates, seats and flights by airline at SEA
| Airline | Gates held | Departures a day | Seats out a day | Share of seats | Seats per departure | Regional jets | Median turn | Tows a week |
|---|---|---|---|---|---|---|---|---|
| Alaska | 44 | 307 | 44,800 | 54% | 146 | 28% | 75 min | 140 |
| Delta | 19 | 159 | 22,447 | 27% | 141 | 37% | 74 min | 19 |
| United | 5 | 30 | 4,724 | 6% | 158 | 17% | 74 min | 8 |
| American | 3 | 26 | 4,287 | 5% | 163 | 22% | 64 min | 4 |
| Southwest | 3 | 23 | 3,818 | 5% | 164 | 0% | 56 min | 4 |
| Common use (shared) | 19 | |||||||
Average of 16 full days, Oct 1 to Oct 21, 2026. Gates held = the airline flying the gate most (regional partners count as their brand); 4 gates saw few or no flights (not in use or under repair). Seats are capacity, from each airline’s seat map per aircraft type; 2% of flights have no seat count yet.
On-time departures by airline at SEA
81% of departures left the gate on time (less than 15 minutes after their scheduled time). Airlines with 10+ departures a day.
| Airline | Departures a day | On time | 15+ min late |
|---|---|---|---|
| United | 30 | 85% | 15% |
| Delta | 159 | 85% | 15% |
| Alaska | 307 | 82% | 18% |
| American | 26 | 75% | 25% |
| Southwest | 23 | 56% | 44% |
On time = left the gate less than 15 minutes after its scheduled time. Average of 16 full days.
What size aircraft SEA’s gates handle
Gates by the largest aircraft seen there at least twice. A gate that takes a wide-body also takes anything smaller.
Airlines at SEA: terminals, gates and nonstop routes
Other airlines
Regular flights, but no SEA gate listed in the flight data, so not on the map: EM (88 flights to Bellingham, WA, Port Angeles, WA and Orcas Island, WA).
Seen on only one of the full days collected (charters and occasional flights): Air Incheon (9 flights); L7 (6 flights); OY (3 flights); Allegiant (2 flights).
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SEA gate questions
How many gates does Seattle Airport (SEA) have?
Seattle Airport (SEA) has 97 gates, with about 581 airline departures a day. Alaska has the most (44), followed by Delta (19).
Which airline has the most gates at Seattle Airport (SEA)?
Alaska, with 44 of the 97 gates at SEA (the airline flying each gate most; regional partners count as their brand).
How many flights a day leave Seattle Airport (SEA)?
About 581 airline departures a day (Oct 1 to Oct 21, 2026).
Which terminal is Alaska in at SEA?
Alaska flies from Concourses C, N and D at Seattle Airport (SEA).
How many gates does Alaska have at SEA?
44 gates, with about 307 departures and 44,800 seats a day.
How many gates does Delta have at SEA?
19 gates, with about 159 departures and 22,447 seats a day.
How many gates does United have at SEA?
5 gates, with about 30 departures and 4,724 seats a day.
How many seats leave SEA each day?
About 83,569 seats on 581 airline departures a day (average of 16 full days, Oct 1 to Oct 21, 2026).
What is the typical turn time at SEA?
75 minutes at the gate from arrival to departure (median of every turn measured).
Which airline leaves SEA on time most often?
United Airlines: 85% of its departures left the gate less than 15 minutes after their scheduled time, against 81% for all airlines at SEA (16 full days, Oct 1 to Oct 21, 2026).
How often do flights at SEA go back to the gate after pushing back?
15 departures in 16 days probably went back to the gate before taking off (a mechanical problem, fuel, a passenger taken off), and 3 came back and changed planes.
How many aircraft tows happen at SEA?
About 177 tows a week: a plane that arrives at one gate and leaves from another was towed between them. Planes we didn't see arrive aren't counted.