The saltwater crocodile has a longer muzzle than the mugger crocodile: its length is twice its breadth at the base. The saltwater crocodile has fewer armor plates on its neck than other crocodilians, and its broad body contrasts with that of most other lean crocodiles, leading to early unverified assumptions that the reptile was an alligator.
An adult male saltwater crocodile's weight is 600 to 1,000 kilograms (1,300–2,200 lb) and length is normally 4.1 to 5.5 metres (13–18 ft), though mature males can be 6 metres (20 ft) or more and weigh 1,300 kilograms (2,900 lb) or larger. This species has the greatest sexual dimorphism of any modern crocodilian, with females being much smaller than males. Typical female body lengths in the range of 2.1 to 3.5 metres (7–11 ft). The largest female on record measured about 4.2 metres (14 ft). The mean weight of the species as a whole is roughly 450 kilograms (1,000 lb).