How long is the biggest plane in the world?

The biggest wing span of any aircraft ever built was that of the Hughes H-4 Hercules, better known as the Spruce Goose, built in the U.S for transporting military equipment, it is also the largest aircraft in the world the project cost NASA nearly 950 million to over 1.5 billion dollars. It's wing span is 350 feet 11 inches (98.54 metres), bigger than the A380 Airbus and the Antonov An-225.