Which is the thickest tree according to size of trunk?

The thickest tree in terms of trunk size is the General Sherman tree, a giant sequoia (Sequoiadendron giganteum) located in California's Sequoia National Park. It has a trunk diameter of about 36.5 feet (11.1 meters) at its base. This massive tree is renowned not only for its thickness but also for being one of the largest living trees by volume.