The wingspan of an eagle varies significantly depending on the species. It may be less than 1 meter (3.28 feet) in some species and greater than 2.40 meters (7.87 feet) in others.

The smallest known eagle species in the world, the Great Nicobar serpent eagle (Spilornis klossi), has a wingspan of 0.85–0.95 meters (2.78–3.11 feet). It is endemic to the Great Nicobar Island and the adjoining islands in the Indian Ocean.

Some other eagles with a small wingspan are the Philippine serpent eagle (Spilornis holospilus) of the Philippine archipelago, with a wingspan of 1.05–1.20 meters (3.44–3.93 feet); little eagle (Hieraaetus morphnoides) of Australia, with a wingspan of 1.10–1.36 meters (3.60–4.46 feet); pygmy eagle (Hieraaetus weiskei) of New Guinea, with a wingspan of 1.12–1.26 meters (3.67–4.13 feet); and booted eagle (Hieraaetus pennatus) of Europe, Africa, and Asia, with a wingspan of 1.13–1.38 meters (3.70–4.52 feet).

On the upper end of the wingspan spectrum is the Steller’s sea eagle (Haliaeetus pelagicus), with a wingspan of 2.20–2.45 meters (7.21–8.03 feet). Some reports suggest that it can attain wingspans of 2.70 meters (8.85 feet). Based on its wingspan and weight of 5–9 kg (11–20 pounds), it holds the Guinness World Record for the largest eagle in the world. It is found in far eastern Russia, Japan, North Korea, and South Korea.

Other contenders for the position of the largest eagles based on wingspan are:

• White-tailed eagle (Haliaeetus albicilla) of Europe and Asia, with a wingspan of 1.93–2.44 meters (6.33–8.00 feet)
• Bald eagle (Haliaeetus leucocephalus) of North America, with a wingspan of 1.68–2.44 meters (5.51–8.00 feet)
• Martial eagle (Polemaetus bellicosus) of Sub-Saharan Africa, with a wingspan of 1.88–2.27 meters (6.16–7.44 feet)
• Wedge-tailed eagle (Aquila audax) of Australia and New Guinea, with a wingspan of 1.82–2.32 meters (5.97–7.61 feet)
• Harpy eagle (Harpia harpyja) of Central and South America, with a wingspan up to 2.24 meters (7.34 feet)
• Golden eagle (Aquila chrysaetos) of Asia, North America, Europe, and North Africa, with a wingspan of 1.85–2.22 meters (6.06–7.28 feet)
• Philippine eagle (Pithecophaga jefferyi) of the Philippines, with a wingspan of 1.84–2.02 meters (6.03–6.62 feet)

The largest eagle to have ever existed—the Haast’s eagle (Hieraaetus moorei)—had an impressive wingspan of 3 meters (9.84 feet). This gigantic raptor of New Zealand roamed the Earth as recently as 15th century ᴄᴇ and became extinct when its primary prey, the moa, was hunted to extinction.