Boeing 787 Comfort Tradeoff: Better Cabin Air, Tighter Economy Seats on Many Airlines

If you are booking economy on a Boeing 787, the useful question is not only whether the flight is on a Dreamliner. It is also how many seats are in each economy row. An analysis published Oct. 25, 2026, by Simple Flying argues that the 787's cabin-environment gains come with a seat-width tradeoff, and that tradeoff depends on the airline's layout.

What the 787 changes in the cabin

Cabin altitude. Cabin altitude is the altitude that the pressurized air inside the plane is equivalent to. It is not the plane's actual cruising height. Simple Flying reports that the 787 holds its cabin at about 6,000 feet. Conventional aluminum jets such as the 767 and A330 are capped at roughly 8,000 feet at typical cruise. According to the same report, carbon-fiber composites make up roughly 50% of the 787's airframe by weight, and that is what lets the fuselage withstand the higher internal pressure.

Simple Flying links the design to a New England Journal of Medicine study. That study found blood oxygen saturation fell by an average of 4.4 percentage points after three to nine hours at a simulated 8,000-foot cabin altitude. Simple Flying says the 787 keeps blood oxygen closer to sea-level norms. That is the publication's conclusion. The material we reviewed does not include a 787-specific measurement.

Humidity and air supply. Most conventional airliners pressurize the cabin with bleed air, which is air drawn from the engines' compressor stages. The Points Guy noted this in a 2019 explainer. The 787 instead uses electrically driven compressors to bring in outside air. Simple Flying says the 787 also has active humidifiers that push relative humidity up to 15% to 25%. It compares this with under 10% on other airliners, a figure it attributes to TravelGrom.Windows and ride. Per Simple Flying, the windows measure 10.7 by 18.4 inches, up to 65% larger than standard passenger aircraft windows. They use electronic dimming with five opacity levels instead of pull-down shades. One limit: flight attendants can centrally override individual window settings. Both publications describe sensor-driven flight controls that automatically counter turbulence.

The tradeoff: seat width in economy

Simple Flying says Boeing designed the roughly 215-inch-wide 787 cabin around eight economy seats per row in a 2-4-2 layout. That layout gives seats about 18.5 inches wide. Only a few carriers, such as ANA and JAL, stuck with it. Other operators chose nine across (3-3-3) to raise density, which narrows seats to 17.0 to 17.3 inches. By the same account, the Airbus A350's 221-inch cabin fits 18-inch seats nine across.

Simple Flying frames the choice as weighing the 787's physiological benefits against tighter lateral seating.

What this means when you book

Our inference: the sources describe cabin altitude, humidity and windows as features of the aircraft itself. Economy seat width, by contrast, is an airline configuration choice. For economy travelers who prioritize elbow room, that makes the airline's seat map at least as important as the aircraft type. Note that neither source breaks down humidity settings by operator, so treat the humidity range as a design capability, not a guarantee for your flight.

If a smoother ride matters most to you, Simple Flying says seats over the wing, near the aircraft's center of gravity, get the most stable ride. The rear cabin has a longer moment arm, meaning it is farther from the center of gravity, so it moves more.

Limits: these are design specifications and the publications' interpretations of their effects. They are not outcomes measured on specific flights. The seat widths are Simple Flying's figures. Check your airline's own seat map for the cabin you will actually fly.