Grizzlies can weigh up to a thousand pounds. Kodiak bears (Alaskan Grizzly Bears) can get as large as 1500 pounds. Polar bears are approximately the same size as Kodiaks, and can also weigh as much...
there are no different sorts of polar bears, like there are different sorts of cats. There are only the stages of life a polar bear goes through, from cub to adult.