The polar bear (Ursus maritimus) is the world’s largest land carnivore. These powerful mammals are adapted to the harsh Arctic environment, spending most of their lives on the sea ice hunting for seals. Obtaining precise, scientifically verified measurements of the largest specimens is extremely difficult due to the vastness and remoteness of their habitat. This logistical challenge has led to a widely cited historical record that remains the subject of some debate among researchers.
The Confirmed Record Holder
The largest polar bear ever recorded was a massive male specimen documented in the mid-20th century. This bear was shot in 1960 in the Kotzebue Sound area of northwestern Alaska. Its reported weight was 2,209 pounds (1,002 kilograms).
The carcass measured 11 feet and 11 inches in total length, often approximated to nearly 12 feet when the bear was standing on its hind legs. This extraordinary size is approximately double the weight of a typical large adult male polar bear today.
While this figure is widely accepted as the record, it lacks modern scientific verification because the measurement was taken outside of a controlled research setting. The skull, which would have provided definitive biological confirmation of its size, was unfortunately lost. For comparison, one of the largest scientifically verified males, captured in 1985, weighed 1,785 pounds (810 kg), solidifying the 1960 Alaskan bear as a significant outlier.
Average Size of Adult Polar Bears
The record-holding bear contrasts sharply with the typical size of the species, which exhibits pronounced sexual dimorphism. Fully grown adult males, known as boars, typically range in weight from 661 to 1,764 pounds (300 to 800 kg) and measure between 7.2 and 8.2 feet (220 to 250 cm) in length. These males can be two to three times heavier than the females.
Adult females, or sows, are substantially smaller, with an average weight between 331 and 992 pounds (150 to 450 kg) and a length of 5.9 to 6.9 feet (180 to 210 cm). A bear’s weight fluctuates significantly throughout the year, peaking in late spring after a successful winter hunting season and dropping considerably by the end of the summer fasting period. Size can also vary geographically, with some subpopulations having historically yielded larger average body masses for males.
Why Measuring Polar Bears Is Difficult
Obtaining scientifically rigorous weight and length data for polar bears presents considerable logistical difficulties, which explains why historical records are often based on unverified reports. The process requires a research team to chemically immobilize the animal with a dart, a procedure that is costly and involves risk to the bear, especially when working on broken sea ice.
Once sedated, researchers must use heavy, specialized equipment, such as a tripod and scale, to lift and weigh the animal, which is challenging in the remote Arctic environment. Because direct weighing is impractical, scientists often rely on estimation formulas that use measurements like body length and chest circumference (girth) to calculate an approximate weight.
For bears that cannot be safely approached, researchers may use a visual “standardized fatness index” to assess body condition, but this provides a score, not a precise weight. Due to remote locations, dangerous ice conditions, and the need for sedation, accurate, direct-weighing data on the largest individuals remains relatively rare.