Top 10+ of the biggest jets ever made, ranked by size

Airbus BelugaXL -- 40,956 square feet

Undoubtedly one of the most unique-looking aircraft in the sky, the BelugaXL, as its name suggests, looks like a giant flying beluga whale. It was designed to replace Airbus' existing fleet of five Beluga aircraft, whose job was to transport aircraft parts between the company's various facilities around the world. Airbus has manufacturing facilities across Europe and in China, and the ability to quickly transport parts like pre-assembled wings between those facilities is vital to keeping its manufacturing operations running smoothly.

The first BelugaXL was assembled in 2018 and all five planned units are scheduled to be completed by the middle of this decade. The first examples are already in service, and can occasionally be seen at passenger airports, including in 2022 when London Luton Airport passengers were treated to the sight of it performing a training exercise in between scheduled flights. The aircraft's 207 ft length and 197 ft 10 in wingspan doesn't fully describe the aircraft's size — instead, it's the bulbous fuselage that's the real headline feature, with a huge 30% increase in cargo capacity compared to the original Beluga, and a maximum payload of 51 tons.

Airbus A340-600 -- 51,469 square feet

With room for 320 passengers in standard configuration and up to 475 passengers in high-density configuration, the Airbus A340-600 is one of the European firm's largest aircraft in production. It's the longest variant of the A340 line, and boasts a range of 7,800 nautical miles, enabling it to connect many of the world's largest hubs. The first example was delivered in 2002, and since then, a number of the world's largest carriers have taken delivery of the aircraft, including Emirates and Lufthansa.

To achieve the extra cabin space compared to other A340 variants, Airbus increased the length of the fuselage, making it the manufacturer's longest jet in operation today. Its flight deck is also designed to be as similar as possible to other A340 variants in order to reduce pilot training time — it reportedly only takes a day or two of training for pilots to be certified to fly the A340-600 if they've already flown other models in the line.

Antonov An-124-100 Ruslan -- 54,480 square feet

While its cargo capacity falls a little short of its now-destroyed successor, the An-225, the Antonov An-124-100 Ruslan is still a formidable cargo carrier. In fact, it's now the largest surviving cargo plane in the world. In 1994, it set the world record for carrying the heaviest piece of cargo, a General Motors locomotive, from Canada to Ireland. The trip required multiple refueling stops and took 12 hours in total. The total payload, including the equipment required to secure the locomotive, was 146 tons.

The aircraft was originally built by the Soviet Union, and all remaining examples still in service today are either owned by Ukraine or Russia. Several of the Russian-owned aircraft are currently grounded abroad after sanctions prevented their use, but others remain in the country and are reportedly used in the war effort. Likewise, Ukraine's Ruslans have been used to help the country ship in military equipment from various allies around the world.

Lockheed Martin C-5M Super Galaxy -- 55,210 square feet

The C-5M Super Galaxy is the largest aircraft in the U.S. Air Force's fleet, with a cargo capacity of 281,001 pounds. It's used to transport enormous amounts of equipment to U.S. bases (and those of allies) across the world, and features several innovations to make it as efficient as possible. That includes the dual loading doors — both the front and rear ends of the aircraft lift open to allow cargo to be loaded and unloaded simultaneously.

The aircraft can carry up to five helicopters, and features drive-on ramps at both ends of the cargo bay with room for two rows of vehicles to be carried. It can be refueled in mid-air, and so theoretically has unlimited range with the appropriate support. The C-5 Galaxy has been flying since 1970, but after several decades of service, a modernization program began around the turn of the century, leading to the updated "C-5M" aircraft in service today.

Boeing 747-8 -- 56,145 square feet

After 56 years of production, Boeing recently ended production of its veteran 747 model, with over 1,500 examples of the aircraft sold. The most recent iteration of the aircraft, the 747-8, took its first flight in 2010, and boasted an even larger wingspan than its predecessor, at 250.2 feet. Among the last customers of the 747-8 was the U.S. Air Force, which commissioned replacements for the president's Air Force One fleet. The latest plane boasts a variety of improvements over the outgoing 747-200 presidential aircraft, including a longer range, lower emissions, and a faster cruising speed.

The 747-8's cruising speed is the fastest of any passenger jet in the world, at 0.855 Mach. While the aircraft is no longer in production, its enduring popularity among both passengers and operators will ensure it remains a familiar sight in the skies for many decades yet. However, its fate was sealed long ago by the arrival of newer, more efficient planes and higher passenger demand for short-haul flights, so despite the 747's iconic status, it was always going to end up on the chopping block.