The biggest living thing on the planet is a Redwood tree called General Sherman; not the tallest tree but by volume. It lives in the Sequoia National Park in California. I was fortunate to visit in 2007. A bigger Redwood lived in California until it was cut down in 1940 and was estimated to have been 15-25% bigger than General Sherman. The pictures give some idea of it size. It stands 275 feet (83 m) tall, and is over 36 feet (11 m) in diameter at the base. Sequoia trunks remain wide high up. Sixty feet above the base, the Sherman Tree is 17.5 feet (5.3 m) in diameter.