Passengers sitting in premium economy are more likely to be upgraded than any other class

PREMIUM class passengers are more likely to get upgraded for free than any other class, according to experts.

This is because of the size of the classes and the likelihood of seats being full.

According to , airlines often have large economy cabins and large business class cabins.

Most airlines will often only bump passengers up once class - so economy may be bumped to premium economy and premium economy passengers will be put into business class.

However, they explain that the "load factor" - how many passengers are on board - is high in basic economy, yet airlines still over-sell seats.

The website says: "Let’s assume, as unlikely as it is, that everyone in economy turns up — in this example, 333 economy passengers when the aircraft only seats 303 in economy.

"BA will only likely have oversold by that much if there are seats available in higher cabins (where it’ll also oversell but will presumably have similar no-shows, misconnections and last-minute changes).

"So, assuming that there are 30 seats available in higher cabins, BA will begin upgrading 30 passengers from economy to premium economy.

"The premium economy cabin on the A380 has space for 55 passengers.

"If that cabin was full, potentially more than half of the passengers from premium economy would be upgraded to business class."

The method is known as "rolling forward" which is when passengers move up a cabin.

They add: "The percentage of passengers being upgraded from economy is usually in the single digits whilst on busy routes, it’s not unusual for a third (or even more) of the premium economy cabin to be moved forward."

Premium economy often offers extra legroom, better amenity kits and meal options as well as bigger seats.

The Points Guy reviewed all four British Airways classes - and premium economy (also known as World Traveller Plus) came out as the best value for money.

Other ways to get free upgrades are to sign up to loyalty cards and frequent flyer schemes to build a relationship with the airline.

A flight attendant has revealed that buying a £5 gift card for crew could also persuade them to bump you up.

Checking in online could be ruining your chance of a free upgrade.