US Aviation Market Data Insights

Find answers to your questions about the US aviation market, with flight data insights and analysis powered by OAG's Schedules Analyser.

• Which are the top airlines in the USA?
• What's the country's busiest airport?
• Which US domestic flight route is busiest?
• Is there more domestic or international capacity in the US aviation market?
• Exclusively available to download: US monthly airline seats data from 2019-present day.

The data is updated monthly. Seats are calculated as departing seats (one-way).

• American Airlines remains the biggest carrier in the US this month with 21% of the market, 23.2m seats.
• Delta Air Lines and SouthWest Airlines remain a close second and third largest, with 19% and 18% share respectively again this month. 
• Spirit Airlines decreased capacity significantly again this month by 28% vs July 24. Spirit continues to restructure under bankruptcy with a view to emerging leaner and more stable.
• Frontier Airlines also reduced capacity by 12% in July 25.
• Percentage-wise, Allegiant Air continued to add most capacity within the Top 10, up by 10%.
• The Top 10 airlines provide 91% of US Capacity.                                                    
  
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• United Airlines added the most seats again this month, increasing seats by 1.4m vs July 24.  
• Delta Air Lines increased capacity by 701,400 seats this month and American by 622,100 seats compared with July 24.
• Percentage-wise Breeze Airways increased capacity at the fastest rate of 43%, 233,900 additional seats.

• The busiest route this month is New York La Guardia to Chicago with 307,000 seats, an increase of 6% capacity vs July 24.
• Capacity grew at the fastest rate on the Los Angeles to Chicago route again this month, growing by 10% vs July 24.
• Capacity decreased most on the Anchorage to Seattle and Honolulu to Kahului routes, by 12% and 11% respectively vs July 24. 
• The Denver - Chicago route displaced Atlanta - New York La Guardia, moving from 14th position last month to 10th in July 25.

• The state of Illinois saw the largest increase in seats again this month, with capacity increasing by 429,500 seats vs July 24.
• Percentage wise capacity increased most in Michigan and Tennessee, up by 9% and 8% respectively.
• Capacity decreased most in North Carolina, by 178,400 seats, followed by Minnesota by 111,400 seats vs last year.

To view US flight capacity statistics from 2019-2025, click the button below to download the data.

*As of July 2025, international capacity is reported on a two-way basis (previously one-way departing).