Britain's royal family spends a pretty penny to fly — and does so quite often.

As royals gather for the Duke of Edinburgh's ceremonial funeral on Saturday, private jet company Stratos Jet Charters analyzed the royal's financial travel reports over the last five years. It discovered that top members of the U.K. monarchy amassed nearly 550,000 in airline miles, with 72-year-old Prince Charles traveling the most compared to his royal counterparts.

The Prince of Wales flew 25 times over the past half a decade — totaling 120,000 miles and costing over $3.3 million. Charles’ longest trip, which came out to 18,000 miles, took place in 2017 and led him through Singapore, Brunei, Malaysia and India.

Meanwhile, a 2019 extensive tour around the Caribbean cost well over $573,000 — the Prince's most expensive trip in recent years.

According to the report, 61% of the royal's official international travel occurred via private jets.

Prince Charles and Camilla flew private the most, with 18 and 12 trips, respectively. However, Queen Elizabeth, along with consort Prince Philip prior to his death on Friday, were most likely to travel private. Despite only making two international trips in the last five years, the queen and her consort flew private both times.

In total, the royal family racked up 545,161 miles over 92 trips solely in international business travel between 2015 and 2020, costing a whopping $9 million. Trips within the UK and personal vacations were not included in the calculations.

For context, that number is the equivalent mileage of traveling from the earth to the moon and back again, plus three complete loops of the earth’s circumference.

Harry and Meghan's royal excursions

Prior to exiting the royal family, Prince Harry and Meghan Markle traveled quite often.

At least two trips in the last five years included travel to Botswana, a country that Harry has said he feels "deeply connected to" since the passing of his mother Princess Diana. The round trip total from London to Botswana is 10,570 miles with an estimated private jet cost of $222,512.

In 2017, the couple also enjoyed a vacation to Jamaica for a friend's wedding. Harry flew commercial whereas Meghan took a private jet from Toronto — costing an estimated $63,686 and racking up nearly 3,000 round trip miles.

Out of the top 13 royal members examined for this report, Meghan Markle had the highest average cost of $224,292 per trip. Prince Andrew had the lowest average per trip at $34,722.

Alexandra is a Producer & Entertainment Correspondent at Yahoo Finance. Follow her on Twitter @alliecanal8193