Aboard the major airlines that operate long-haul services out of Sydney and Melbourne, seat width lies in the range between 43-48.25cm. That 5.25cm difference is less than the width of an iPhone. Not much you might think, but a couple of extra centimetres makes a lot of difference on a long-haul flight. Consider that Emirates, an airline known for quality, offers its business class passengers a seat that is just 1.25cm wider than its economy seat aboard its A380 services.