Analysis of Google Trends has revealed searches for ‘how to upgrade flight’ have increased by an impressive 207 percent, and ‘flight upgrade’ searches have spiked 146 percent this year.

This has resulted in both searches soaring higher than in the past 20 years.

As a result, the lifestyle magazine Dailybase has analysed 49 international airlines which offer business class cabins among their fleet to find which are most worth the extra money spent on upgrading.

This was compared to the flyer experience for those travelling in their economy cabins.

The researchers created an index covering several factors that affect the flyer experience. These factors include seat size and type, the difference in seat size between economy and business class for each airline, the airline’s in-flight entertainment and food reviews, the availability of Wi-Fi onboard, and each airline’s overall Tripadvisor review score.

Each of the factors was then allocated an index score, weighted, and collated to create the ultimate ranking of the airlines most worth upgrading your ticket with.

The study found Singapore Airlines is the best airline to upgrade on, scoring an impressive 87.46 percent in the index. This equated to a total index score of 61.23 out of 70.

Singapore Airlines’ standout difference between its economy and business class cabins is the comfort provided by not only seats that turn into flat beds but also the extra 9.5-inch width the seats have on average.

This is the most of any of the 49 airlines considered. In addition to the four out of five stars it has gained, the airline’s in-flight entertainment, food, and overall customer experience have been positively reviewed, according to SKYTRAX and Tripadvisor.

Spanish airline Iberia was ranked the second-best airline most worth upgrading a ticket on, with an overall index score of 57.82 out of 70 across all factors considered, totalling 82.59 percent in the study.

According to the findings, business class passengers with the airline will be able to enjoy the luxury of some of the most legroom of any business passenger across all the airlines analysed.

The study found an average of 40 inches more legroom in business compared to the airline’s economy cabins, as identified on Tripadvisor‘s Seat Guru comparison charts.

Delta Air Lines ranked first among US-based airlines analysed in the study and took third place overall, achieving 81.64 percent in the index. With a total score of 57.15 out of 70, Delta is also the only North American airline to place in the top 10.

Equalling first place airline Singapore Airlines, Delta Air Lines has also received an overall Tripadvisor review score of four out of five stars, having won the website’s Travellers’ Choice Awards numerous times and gaining more than 25,000 ‘excellent’ reviews by customers.

Top 10 airlines most worth upgrading:

1. Singapore Airlines – 87.46 percent

2. Iberia – 82.59 percent

3. Delta Air Lines – 81.64 percent

4. Qatar Airways – 81 percent

5. Air New Zealand – 80.87 percent

6. Virgin Atlantic – 78.72 percent

7. Japan Airlines – 78.18 percent

8. Korean Air – 78.18 percent

9. SAS Airlines – 77.61 percent

10. Hong Kong Airlines – 77.42 percent