Leading flights metasearch site Skyscanner has applied mathematics to the vexed question of what makes for the perfect flight.
On the back of the results of a survey of 2,000 people the firm weighed up factors such as flight time, food, legroom and punctuality.
It then turned to Dr Eugenia Cheng, senior lecturer of pure mathematics at the University of Sheffield, to come up with a mathematical formula to help travellers.
The formula is based on the factors that respondents cited as most important when booking a flight – time of day, punctuality and legroom – and calculates a flight perfection scoring out of a possible 20 marks (15 in economy).
Perfection is a flight in the morning, with legroom of 40 inches and a punctuality score close to 100.