The Antonov 124 is a strategic heavy-lift transport aircraft that was developed by the Soviet Union in the 1980s. It is one of the largest military transport aircraft in the world, and it can carry oversized cargo such as tanks, helicopters, and satellites.
The Airbus 380 is a wide-body, long-range commercial passenger airliner that was developed by France in the 2000s. It is the largest passenger aircraft in the world, and it can carry up to 853 passengers in a single-class configuration.
The Antonov 124 has a length of 226.7 feet (69.1 meters), a wingspan of 240.5 feet (73.3 meters), and a height of 68.2 feet (20.8 meters). The Airbus 380 has a length of 239.5 feet (73 meters), a wingspan of 261.8 feet (79.8 meters), and a height of 79.1 feet (24.1 meters). Based on these dimensions, we can see that the Airbus 380 is longer, wider, and taller than the Antonov 124.
Size is not only about dimensions but also about weight and volume. The Antonov 124 has an empty weight of 385,809 pounds (175,000 kilograms), a maximum take-off weight of 892,872 pounds (405,000 kilograms), and a cargo volume of 46,000 cubic feet (1,300 cubic meters). The Airbus 380 has an empty weight of 610,240 pounds (276,800 kilograms), a maximum take-off weight of 1,234,589 pounds (560,000 kilograms), and a passenger volume of 40,978 cubic feet (1,160 cubic meters). Based on these measures, we can see that the Airbus 380 is heavier and has more volume than the Antonov 124.
So we do not say which aircraft is bigger. It depends on what aspect of size you are interested in. If you are looking at the external dimensions, then the Airbus 380 is bigger than the Antonov 124 in terms of length, wingspan, and height. If you are looking at the weight and volume, then the Airbus 380 is bigger than the Antonov 124 in terms of empty weight, maximum take-off weight, and total volume. If you are looking at the cargo or passenger capacity, then the Antonov 124 has more cargo volume than the Airbus 380, while the Airbus 380 has more passenger volume than the Antonov 124.