How Strong Is a Crocodile Bite? Bite Force Records Explained

The record: 16,414 newtons

The record comes from a study led by Gregory Erickson of Florida State University, published in the journal PLoS ONE in 2012. His team measured the bite forces of adults of all 23 living crocodilian species, including crocodiles, alligators, caimans and the gharial, with tests carried out in Florida and Australia.

The highest value came from a large male saltwater crocodile: 16,414 newtons, or about 3,690 pounds-force. That is the strongest bite force ever recorded for any animal. The same paper noted that the highest value then known for a mammalian carnivore was about 4,500 N (1,011 lbf) for the spotted hyena, less than a third of the crocodile’s.

How do scientists measure a crocodile’s bite?

Researchers use a bite bar: a padded steel sensor that the crocodile bites down on. Crocodilians bite readily when something touches the inside of the mouth, so the animal is restrained, the bar is placed between the back teeth and the crocodile is allowed to bite several times. The highest reading is recorded.

Bite force is a force, measured in newtons (N) or pounds-force (lbf); 1 lbf equals about 4.45 N. Popular articles often quote crocodile bites in psi (pounds per square inch), but psi is a unit of pressure. The pressure under a single tooth tip is far higher than the overall bite force suggests, because the force is concentrated on a tiny area, and the 2012 study found that crocodilian tooth pressures exceed those reported for any other animal.

Bite forces of crocodilians compared

The Nile crocodiles tested in the 2012 study were small adults, so their figures say little about a large male Nile crocodile. A widely quoted value of about 22,000 N (5,000 lbf) for a big Nile crocodile comes from a field test made for a television documentary rather than a peer-reviewed study. Some sources also give a higher figure for a large American alligator, around 13,000 N (2,960 lbf). For more animals, see strongest bite force.

Why the saltwater crocodile tops the list

The main finding of the 2012 study was simple: across all crocodilians, bite force depends mostly on body size. Snout shape and diet made surprisingly little difference. A crocodile with a broad snout and a crocodile with a moderately slender one bit with similar force if they were the same weight. Only the very narrow-snouted gharial bit clearly weaker than expected.

Because the saltwater crocodile is the largest living reptile, it bites hardest. Using how bite force increased with body weight, the researchers estimated that a scientifically documented 6.7 m (22 ft) saltwater crocodile weighing about 1,300 kg (2,900 lb) would have produced roughly 27,500 to 34,400 N (6,200 to 7,700 lbf). The same method suggested that the extinct giant Deinosuchus, about 11 m (36 ft) long, may have reached over 100,000 N (23,000 lbf).

Strong closing, weak opening

Crocodile jaws are built for clamping. Huge muscles that close the jaws fill bulges at the back of the skull, and the jaw joint gives them excellent leverage. The muscles that open the jaws, by contrast, are small and weak. That is why trained handlers can keep a restrained crocodile’s mouth closed with a few turns of tape. This is a job for professionals with the crocodile already secured, never something to attempt with a wild animal.

The teeth are cone-shaped pegs designed to grip and puncture rather than slice. A crocodile seizes prey, holds on with its enormous bite and then drags it underwater, shakes it or spins in a death roll to tear off pieces it can swallow. Crocodilians replace worn or broken teeth throughout life.

Myths about crocodile bites

Myth: crocodiles have the strongest bite because of their snout shape. The 2012 study found that body size, not snout shape, explains most of the differences between species.

Myth: the crocodile bite force is 5,000 psi. No peer-reviewed study supports this number, and psi is the wrong unit for overall bite force. The highest measured value is 16,414 N (3,690 lbf).

Myth: the great white shark has a stronger measured bite. Nobody has measured a great white’s bite directly. A 2008 computer model estimated up to about 18,200 N (4,095 lbf) for a 6.4 m (21 ft) shark, but that is an estimate. Even if the model is right, it would put the shark in the same range as the largest crocodiles, not far above them.