Single-aisle

A narrow-body aircraft or single-aisle aircraft is an airliner arranged along a single aisle permitting up to 6-abreast seating in a cabin below 4 metres (13 ft) of width. In contrast, a wide-body aircraft is a larger airliner usually configured with multiple aisles and a fuselage diameter of more than 5 metres (16 ft) allowing at least seven-abreast seating and often more travel classes. The highest seating capacity of a narrow-body aircraft is 295 passengers in the Boeing 757–300, while wide-body aircraft can accommodate between 250 and 600 passengers.

Between 2016 and 2035, Flightglobal expects 26,860 single-aisles to be delivered for almost $1380 billion, 45% Airbus A320 family ceo and neo and 43% Boeing 737 NG and max. The re-engined Airbus A320neo and Boeing 737 MAX have longer range, enabling carriers to launch new routes with not enough capacity to require a widebody like for transatlantic flights to secondary destinations.

2-abreast aircraft seats typically 4 to 19 passengers, 3-abreast 24 to 45, 4-abreast 44 to 80, 5-abreast 85 to 130, 6-abreast 120 to 230. For the flight length, medium-haul aircraft are typically the Airbus A320 and Boeing 737, while regional airliners typically cover short haul.

Two abreast cabin.

A four abreast cabin.

This Virgin America Airbus A320 is an example of a narrow-body passenger six abreast cabin.

...
Wikipedia