Economy class seats on Delta: The standard seat width typically ranges from 17 to 18.5 inches, depending on the plane. Seat pitch ranges from 30 to 33 inches.

• Delta First Class Seat For Passengers: If you have taken an upgrade to first-class on a Delta flight may be the only way to ensure you don't get kicked off your flight. Since the seats in the premium are much wider and typically offer a console between the seats. It is for those who are large travelers and does not encroach on the other seat.

A Guide To Delta's Customer Size Policy
Under Delta's additional and comfort seat policy, obese passengers can purchase an additional seat for their comfort during a trip. Delta does not require passengers who need a seat belt extender or who cannot lower the armrest to purchase an additional seat. If a passenger occupies an ill-defined “too much space,” they may be asked to move or take a later flight.