How to Calculate Dasha and Antardasha in Vedic Astrology
1. In this chapter is explained the method of calculating the antar dasa and
pratyantar dasa. There are antar dasas of all the nine planets in a dasa. For
example, in the dasa of the Sun there will be the antar dasas of the Sun and all the
other planets. The first antar dasa is of the same planet who is the lord of the dasa.
For example, in the dasa of Jupiter the order of antar dasas will be Jupiter, Saturn,
Mercury, Ketu, Venus, the Sun, the Moon, Mars and Rahu. In the dasa of Venus the
order of antar dasa will be venus, the Sun, the Moon, Mars, Rahu, Jupiter, Saturn,
Mercury and Ketu.
As there are nine antar dasas in a dasa, there are nine pratyantar dasas in an
antar dasa. The first pratyantar dasa will be of the lord of antar dasa.
Whatever has been here described as effects of any planet, all this should
occur in the planet’s dasa, in his antar dasa and in his pratyantar dasa.
2. The period of antar dasa in a dasa should be calculated by the rule of
three. Suppose if we have to know the duration of antar dasa of the Sun in the dasa
of Venus we should proceed as explained below. In 120 years the Sun’s portion is
of 6years. In 1 year the Sun’s portion will be (6/120)*1. Therefore, in 20 years the
Sun will have Antar Dasa of (6*1/120)*20 = 1 year.
The Sun’s dasa is of 6 years and the dasa of Venus is of 20 years. Therefore
the figures of 20 and 6 have been taken above. The pratyantar dasa in any case can
also be calculated in the same manner. We have found out that in the dasa of Venus
the duration of Sun’s an tar dasa is 1 year. Now let us find out how much will be
the duration of pratyantar dasa of the Sun in his antar dasas.
In 120 years the duration is 6 years
In 1 year it will be (6*1/120) = 1/20 years
(1/20)*360 days = 18 days.
Thus in the dasa of Venus, the duration of the pratyantar dasa of the Sun in
his antar dasa will be 18 days.
These informations are available in readymade tables in the various
Panchangas which can be usefully utilised.
Notes — Shri V. Subrahmaniam Sastry has explained the method of
calculation as under :—
“Multiply the years of maha dasa by the years of the planet whose antar dasa
is required. Divide the period by 120. The quotient will represent the years of antar
dasa. Multiply the remainder by 12 and divide the result by 120. The quotient will
represent the months, multiply the remainder by 30 and divide by 120. The
quotient will give the days and so on. The same process should be adopted for
calculating the sub-divisions. In any dasa the order of the antar dasa is similar to
that in the dasa of the first antar dasa commencing with that of its lord.”
There is an easy method by mean of which the antar dasa can be
independently calculated. This may be helpful at times when the antar dasa tables
are not readily available.
Multiply the number of years of dasa period of the planet by the number of
years of dasa of the period of the planet antar dasa is required. The last figure in
the product always represents the decimal of a month and the rest represents the
total number of months. Then cutting of the last digit of the product, multiuply it
by 3 and keep that figure as days. Suppose we want to find out the antar dasa of
Mercury in the dasa of Saturn. Multiply the dasa period of Mercury 17 years by
that of Saturn viz. 19 years i.e. 19*17 = 323. By adopting the above method the
antar dasa of Mercury will be 32 months and 9 days i.e. 2 years 8 months 9 days.
