The Chaturvimshamsha chart, D-24, is the eleventh of the sixteen divisional charts, formed by dividing each sign into twenty-four parts. It signifies education and learning, formal study, the acquisition of knowledge and skill, and success in academic and scholarly pursuits. It is also called the Siddhamsha. An astrologer consults the D-24 for questions of intellectual aptitude, the course of a person's schooling, and attainment in learning. The chart is one of the shodashavarga, the harmonic subdivisions through which jyotisha magnifies each department of a single nativity. These are the interpretive conventions of the tradition; the divisional charts are a mathematical technique for drawing many focused readings from the one set of planetary positions recorded at the moment of birth.
Its alternate name, Siddhamsha, meaning the accomplished or perfected division, points to the chart's traditional use in judging not merely whether formal education is undertaken but whether real mastery, siddhi, is achieved in whatever is studied, a distinction some commentators draw between the Chaturvimshamsha and a simple reading of the fifth house of the Rashi chart, which covers learning and intelligence more broadly without singling out attainment as sharply. Like the other vargas finer than the Dwadashamsha, the exact classical rule for locating its twenty-four divisions is less uniformly transmitted than for the D-9 or D-10, and different manuals present variant starting conventions.