The length of doctoral thesis is generally not calculated by the number of words, but by the number of pages or the range of words. Different schools and majors have different requirements for the length of doctoral dissertations. Generally speaking, the length of doctoral dissertations is much longer than that of master dissertations.

Take the doctoral thesis in America as an example. According to the regulations, a doctoral thesis should contain 100-200 pages, and the number of words in the text should be between 40,000 and 80,000. However, different disciplines and research directions have different requirements for the length of the paper. For example, some doctoral dissertations of science and engineering majors may prefer charts and data, while some doctoral dissertations of humanities and social sciences may need more text narration and analysis.