About 325.8 kilometers. According to Gaode's map, the self-driving distance from Changsha to Tianmen Mountain is about 325.8 kilometers, which takes about 3 hours and 53 minutes, passing through Zhang Chang Expressway. From Changsha to Tianmenshan, you can take the G5894 train at Lugu Station and get off at Zhangjiajie West Station. The whole journey takes about 3 hours and 42 minutes.