Some of the work of Al-Khwārizmī’ is based on Persian and Babylonian astronomy, Indian numbers, and Greek mathematics.

He also writes on mechanical devices like the astrolabe and sundial.

He assists a project to determine the circumference of the Earth and in making a world map for al-Ma'mun, overseeing seventy geographers while systematizing and correcting Ptolemy's data for Africa and the Middle East.

Another major book is Kitab surat al-ard ("The Image of the Earth"; translated as Geography), presenting the coordinates of places based on those in the Geography of Ptolemy but with improved values for the Mediterranean Sea, Asia, and Africa.

Al-Khwārizmī's contributions to mathematics, geography, astronomy, and cartography establish the foundation for innovation in algebra and trigonometry.

His systematic approach to solving linear and quadratic equations leads to algebra, a word derived from the title of his 830 book on the subject, "The Compendious Book on Calculation by Completion and Balancing".

He accomplishes most of his work in the period between 813 and 833.