One of the most significant contributions of Al-Biruni to geography was his refinement of methods for determining the Earth's circumference. Building upon the works of earlier scholars such as Ptolemy and Aristotle, Al-Biruni devised innovative techniques, including trigonometric measurements and astronomical observations, to calculate the planet's size with remarkable accuracy. His calculations were remarkably close to modern estimates, demonstrating his exceptional mathematical and observational skills.

Al-Biruni's works also advanced the field of cartography. He created maps that were based on precise measurements and empirical data, rather than relying solely on conjecture or religious beliefs. These maps not only facilitated navigation and trade but also served as valuable tools for future explorations and geographic studies.

Moreover, Al-Biruni's contributions to ethnography were groundbreaking. He conducted detailed studies of various cultures, documenting their customs, languages, social structures, and religious practices. His comparative approach provided valuable insights into the diversity of human societies, fostering cross-cultural understanding and appreciation.