The largest male, with largely assured references, measured 350 cm (140 in) "over the curves", equivalent to 330 cm (130 in) "between the pegs". The tail length in fully grown males is about 1 m (39 in). Weights of up to 318 kg (701 lb) have been recorded and exceptionally large males weighing up to 384 kg (847 lb) are mentioned in the literature, but according to Mazák, none of these cases can be confirmed via reliable sources.Mazák indicates the typical weight range of historical Siberian tigers as 180 to 306 kg (397 to 675 lb) for males and 100 to 167 kg (220 to 368 lb) for females.
Exceptionally large individuals were targeted and shot by hunters. An unconfirmed report tells of a male tiger shot in the Sikhote-Alin Mountains in 1950 weighing 384 kg (847 lb) with an estimated length of 3.48 m (11.4 ft). In some cases, captive Siberian tigers reached a body weight of up to 465 kg (1,025 lb), such as the tiger "Jaipur."
The skull of the Siberian tiger is characterized by its large size, and is similar to the skull of a lion. It differs in the structural features of the lower jaw and relative length of nasals. The facial region is very powerful and very broad in the region of the canines. The skull prominences, especially sagittal crest and crista occipitalis are very high and strong in old males, and often much more massive than usually observed in the biggest skulls of Bengal tigers. The size variation in skulls of Siberian tigers ranges from 331 to 383 mm (13.0 to 15.1 in) in nine individuals measured. A female skull is always smaller and never as heavily built and robust as that of a male
The ground colour of Siberian tigers' pelage is often very pale, especially in winter coat. However, variations within populations may be considerable. Individual variation is also found in form, length, and partly in colour, of the dark stripes, which have been described as being dark brown rather than black.
The geographical range of Amur tigers in the Russian Far East stretches south to north for almost 1,000 km (620 mi) throughout the length of Primorsky Krai and into southern Khabarovsk Krai east and south of the Amur River. They also occur within the Eastern Manchurian mountain system, which crosses into Russia from China at several places in southwest Primorye. In both regions, peaks are generally 500 to 800 m (1,600 to 2,600 ft) above sea level, with only a few reaching 1,000 m (3,300 ft) or more. This region represents a merger zone of two bioregions: