The tiger is generally considered the largest living cat species.
Tigers are the biggest members of the genus Panthera, although size varies greatly among subspecies, sexes, and habitats. Adult males are substantially heavier than females, and Bengal and Siberian tigers include some of the largest wild individuals recorded. Exceptional males have exceeded 300 kilograms.
The lion is the closest common competitor in size, which causes frequent confusion. Lions can be extremely heavy, but the tiger generally has the greater maximum body mass and length among living wild cats. Jaguars are the largest cats in the Americas, while leopards are powerful but considerably smaller on average.
Size records should be treated carefully: captive animals, unusually fat individuals, disputed historical measurements, and hybrids such as ligers can distort comparisons. The standard zoological answer for the largest living cat species remains the tiger, Panthera tigris.