Sub-divisional charts are a very important part of the process of analysis of a horoscope. They are called Sub-Divisional charts as they are formed by dividing the degree, minutes and seconds of the natal chart into smaller and smaller divisions. The popularly studied sub divisional charts are the Hora, the Drekkana, the Saptamsha, the Navamsha and the Dwadashamsa.

The natal chart, or the Janma Lagna Kundali, is the basic chart which is calculated first. This Lagna chart stays the same for around 2 hours. But, the sub divisional charts keep on changing every few minutes. And, the actual cycle of events of life depends on the Lagna chart and the sub divisional charts both. This difference in the sub divisional charts is the reason why most of the twin siblings do not have exactly similar life despite having similar Lagna chart.

In all there are 144 sub divisional charts which are calculated while making a complete horoscope of a person. But, all of these 144 charts are not taken into consideration when making predictions. It depends on Jyotishi to Jyotishi, according to his experience and preferences, to study the charts which he considers important.