Prana in Hindu astrology is a unit or measurement. The Vimsottari Dasa system is based on a 120 years (maximum) life span of human atmas. It consists of nine mahadashas
- Sun (6 years)
- Moon (10 years)
- Mars of Kuja (7 years)
- Rahu (18 years)
- Jupiter or Brihaspati (16 years)
- Saturn or Shani (19 years)
- Ketu (7 years)
- Venus or Shukra (20 years)
The progression of these dasas would be in the same order.
Each mahadasa is divided into nine segments of unequal length in the same proportion as mentioned above. These segments are called bhuktis. The first bhukti in any mahadasa would be the same as the dasa lord itself.
Just as the mahadasas are divided into bhuktis, the latter in turn are divided into cidras (antaras) and the cidras into sukshmas. Sukshmas are further subdivided into pranas.
In Hindu predictive astrology, for the sake of precision, the dasa, bhukti, cidra, suksha and prana lords all have to be taken into account. For timing events accurately, such an analysis is require, though in practice very few astrologers work beyond antaras.