Why the  dasha periods of planets are different? On what basis these periods are decided?

All 27 Birth Stars (Nakshtras) are divided in 9 Planets. So each Planet gets 3 Birth Star which come exactly after Nine Birth Stars in Zodiac.

At the time of Birth, if Moon is in a particular Birth Star then the Person takes Birth under the Dasa of Planet who owns that Birthstar. The exact calculation of Dasa is a Mathematical Calculation cannot be explained here. However you can find it in many Vedic Astrolgy Books.

All 9 Planets have diiferent Bhukti Kal, it varies from 6 years for Sun to 20 years for Venus. The total of these 9 dasa comes to 120 years. All Dasas have Antardasas also which are agin divided in same 9 Planets.

What kind of effects Native will get from a particular Dasa depends on Planetary Conditions in Horoscope. It could be Bad or Good. One has to take consideration of Gochara transits also while taking decisions.

There are mainly 2 types of Dasa, Vishottari and Ashtottari. I have discussed Vishottari here. Most of the people follow this only. Some may differ.

There are Yogini Dasa nad some other Dasas also but there exact use is little known.

Here are the Planets for first 9 Birth Stars,

Ashwini - Ketu,   Bharani - Venus,   Kruttika - Sun,    Rohini - Moon,   Mrug - Mars,
Ardra - Rahu,     Punarvasu - Guru,   Pushya - Guru   Ashlesha - Saturn

from, 10-18 sequence and 19-27 sequence of Birthstars (Nakshatras).

Normal life span of an ideal Human being is considered to be 120 years. This life span is divided into 9 parts based on the planet rising at the time of Birth ie based on Nakshatra as Milind as Put. EAch Planet has its duration. VIMSHOTTARI MEANS 120 Hence the system of prediction based on 120 years is Vimshottari  Dasa system. While Astottari dasa system recognise 108 years.

The figure 120 is obtained by multiplying the span of a nakshatra by the total number of planets X 9 plantes

The duration of Planets are as under, which are measured in Ghatikas

Sun= 36 days, moon =60 days, Mars =42 days, Rahu= 108 days, Jupiter =96 days, Saturn -114 days, Mercury =102 days, Ketu=42 days and Venus 120 days

Each Nakshtra measures 60 Ghatikas

SUN =60 Ghatikas x 36 days =2160 days which is equivalent to 6 years
Moon =60 Ghatikas x 60 days =3600 days which is equivalent to 10 years
Like wise we get Mars - 7 years, Rahu-18 years, Jupiter-16 years, Saturn 19 years, mercury -17 years, ketu 7 years, and Venus 20 years.

When we add up all the years totally we get 120 years

There are around 30 dasas in vedic astrology among them Vimshottari is popularly used in most places in india. While in Northeastern side Astottari system is used

Basic of Dasa Period and why they are different

It is very interesting question. In Vimshottari dasa, the total Life span is 120 years, which comprises of 9 planets dasa. This 120 years is divided in 12 years each . There are 9 planets + lagna which is 10 in number . 12X10=120 years actually.  Hence it should have been 12 years period each. But the fact is not so. Each planet have there own set of periods in the dasa, like Sun having only 6 years and Saturn having 19 years etc.
The reason for this goes like this

SUN actually has 12 year period, but being eclipsed , the period of SUN is reduced by the Period gained by Rahu, hence Rahu takes away 6 years from SUN and thus SUN has only 6 years in the Dasa Period and Rahu has 18 years. Mars and ketu are similar in nature and being the two children of Shiva, Mars being ruler of the week and 7 days of God is equal to 7 years of Human being and hence they carry only 7 years each in the Dasa Period. This loss of 10 years of the both the planets is taken by their mother Moon and hence the Dasa period of moon is 10 years. Everything being that has taken birth has to grow up and growth is ruled by Upachaya 3,6,10 &11  From Aries the natural lagna these signs are gemini, virgo, capricorn, aquarius  ruled by mercury and Saturn. The period contributed by Lagna is shared by Mercury and Saturn thus. Metonic cycle of Saturn is 19 years and hence the dasa period of Saturn is 19 years, having taken 7 years from lagna, the left 5 years is added to Mercury and thus mercury has dasa period of 12years of its own and 5 from lagna's contribution and thus it has 17 years of dasa period. Jupiter is the Guru of the Vimshottari dasa, and hence it should have total of Sun and moon dasa and so it is 16 years. The balance left over is available to Venus and thus venus dasa is 20 years

Does this explain your doubt?


This is yet another explanation , why the dasa period are different for different planets

It is a very comprehensive post on Dasas by Govardhan ji.

I really liked it. Wonderful !!!

I request others to share their knowledge on such issues.

Any contributor for Dasa Explainations by Planets and their placement in 12 Houses?