Sadvarga is the six divisions in Hindu astrology. Varga means divisions of Rashi (sign). There are six types of divisions of a rashi, known as sadvargas, which are important in natal horoscopy and muhurta astrology.
They are – rashi (30 degrees), hora (15 degrees), drekshana (10 degrees), navamsa (3 degrees and 20 minutes), dwadashamsha (2 degrees and 30 minutes), trimsamsa (1 degree). The lords of divisions are those of their rashis. Hora vargas are only two. Dreskana are three for each rashi; first of the same rashi, second of the fifth rashi, and third of the ninth rashi.
Navamsha runs from Mesha to Dhanu, Makara to Kanya, Tula to Mithuna, and Karka to Mina for Mesha, Vrishabha, Mithuna and Karka, respectively and so on for Simha, Virgo, libra, and Vrischika as also for Dhanu, Makara, Kumbha and Meena Rashi, respectively.
Dvadasamsha division starts from rashi and ends on the twelfth rashi for every rashi. In case of trimsamsa, for odd rashis the divisions are Mesha (1 degree – 5 degrees), Kumbha (6 degrees – 10 degrees), Dhanu (11 degrees – 18 degrees), Mithuna (19 degrees – 25 degrees) and Tula (26 degrees – 30 degrees), while for even rashis they are – Vrishabha (1 degree – 10 degree), Kanya (6 degrees – 12 degrees), Mina (13 degrees – 20 degrees), Makara (21 degrees – 25 degrees) and Vrischika (26 degrees – 30 degrees). These divisions by Parasara are mostly accepted. There are variations in these suggested by Somnatha, Satyacharya and Varahamihira, etc.
Sadvargas are used in natal horoscope (birth chart analysis) to obtain specific results, such as rashi (body – health), hora (wealth), dreskana (siblings), navamsa (life partner), dvadasamsa (parents), trimsamsa (inauspicious and female character). Planets good in divisional charts have bala (strength), which can be calculated.
There are other divisional classifications also, spatavarga (1/7,), (1,10), sodasavarga (1/16) and so on. Sadvargas are very useful for arriving at smaller benefic vargas (belonging to Budha, Shukra and Guru). These are used in fixing the muhurta (auspicious moment) for important occasions. There are as many as 42 subdivisions in rashi chakra, which are used in muhurtas. The details may be seen in Sarvartha Chintamani, Brihat Parasari Hora and Brihat Jataka.