The King Cobra (Ophiophagus hannah) is widely recognized as the world’s longest venomous snake. Native to South and Southeast Asia, this snake inspires awe due to its impressive length and potent venom delivery system. Despite its common name, the King Cobra is not a “true” cobra; it belongs to its own genus, Ophiophagus, which translates to “snake-eater.” Its weight is directly linked to its remarkable length, making it one of the most substantial venomous reptiles on the planet.
The Standard King Cobra Weight and Length
The typical adult King Cobra commonly measures between 10 to 12 feet (3.05 to 3.6 meters) in total length. The weight of a snake this size usually falls into a range of 11 to 20 pounds (5 to 9.08 kilograms). A healthy, mature King Cobra averages around 13 to 15 pounds (5.9 to 6.8 kilograms).
The weight is directly proportional to its length, meaning longer snakes are invariably heavier if they are well-fed. While the average length is impressive, the maximum recorded sizes push these limits further. The longest scientifically confirmed King Cobra reached 18.8 feet (5.73 meters), which is the record for any venomous snake.
A specimen of this maximum length would be significantly heavier than the average, though such extremes are rare. The heaviest recorded King Cobra weighed up to 28 pounds (12.7 kilograms), but weights up to 22 pounds (10 kilograms) are more commonly cited for the largest males. Most individuals encountered will fall within the typical range.
Biological Factors Determining Maximum Size
Biological and environmental variables influence whether a King Cobra reaches maximum size. Like all snakes, King Cobras grow continuously throughout their lives, meaning age is a primary determinant of size. A snake that survives for many years in a resource-rich environment will naturally be much larger and heavier.
Sexual dimorphism also plays a substantial role, with males tending to be much larger than females. Large adult males can weigh up to 22 pounds (10 kilograms), while large adult females may only reach about half that weight, approximately 11 pounds (5 kilograms). This difference is thought to be an advantage in male-on-male combat for mating rights.
Diet and the availability of prey are the most influential environmental factors. King Cobras are specialized predators whose diet consists almost exclusively of other snakes, including large rat snakes and small pythons. Consistent access to these substantial, high-calorie prey items allows a snake to gain the body mass necessary to sustain its frame.
Size Comparison to Other Large Snakes
The King Cobra holds the title of the longest venomous snake globally, but its weight is modest compared to other large snakes. Non-venomous constrictors significantly outweigh the King Cobra, even if they are not substantially longer. For instance, a Green Anaconda or a Reticulated Python can weigh hundreds of pounds, making them far heavier than any King Cobra.
When comparing the King Cobra to other venomous snakes, the contrast shifts from length to girth. The Gaboon Viper, native to Africa, is considered the heaviest venomous snake. Though the Gaboon Viper is much shorter, typically measuring only 4 to 7 feet (1.2 to 2.1 meters) long, it is extremely stout and bulky.
A large Gaboon Viper can easily exceed the King Cobra’s weight, with verified specimens weighing over 25 pounds (11.3 kilograms) with an empty stomach. The King Cobra’s long, relatively slender body is built for agility and length, while the Gaboon Viper’s heavy, cylindrical body prioritizes bulk. This illustrates a clear divergence in evolutionary strategy among the world’s largest venomous species.