Ayanamsa Calculation – How to Calculate Ayanamsa

Ayanamsa Calculation is the difference between Tropical Zodiac Planetary Position and Sidereal Zodiac Planetary Position.

As earth’s precession changes every year, the difference between the tropical zodiac and the sidereal zodiac changes. This difference is called “Ayanamsa” (sidereal difference).

The actual Ayanamsa value must be deducted from the tropical length of each planet to get the sidereal length.


CURRENT AYANAMSA 24 - Feb - 2018

24° 06′ 43″

Tropical Zodiac in Sanskrit is called as Sayana. Tropical Zodiac plays only a small role in Vedic astrology, 99% of calculations based on the Sidereal Zodiac.

This kind of zodiac has the reference point in the stars. The point 0 Aries is interpreted as the beginning of the sign Aries (or the Nakshatra or Star Aswini) in the sky.

Importance of Ayanamsa Calculation

We use the Sidereal Zodiac in Vedic astrology. The difference between the Tropical Zodiac and the Sidereal Zodiac is of great importance.

What modern ephemeris gives us is the Tropical or Sayana Planetary Positions. When the Ayanamsa degree is subtracted from the Tropical Planetary Positions we get Nirayana Planetary Positions. This difference varies with time.

The fundamental metric of Sidereal Astrology|East and West|is the Ayanamsa. This value is critical to the definition and calculation of all Astrological Birth Charts methods and techniques in the Sidereal System.

One small change in the value of the Ayanamsa used collaterally impacts all of the succeeding results.It should be made clear that the house positions obtained from Sayana houses, to be subtracted with Ayanamsa degree from the birth date to compute Nirayana Houses.

There is a difference between Western Astrology and Vedic Astrology in casting the Horoscopes or Birth Chart. The fundamental is that there are two systems of astrology – Saayana (Western) and Nirayana(Vedic).

Western horoscopes take Planetary Positions as observed from the sky and plot as Horoscope also called as Sunsign. In India we subtract from these planetary positions an amount of  ‘Ayanaamsa’ degrees to cast horoscopes – Moonsign – which is not a fixed one and is variable.

what is this ‘Ayanamsa’ ? why should it be subtracted etc.. are different questions. This Ayanamsa increases by an amount of 52 seconds every year. Ayanamsa calculation is of high importance for calculating Planetary Positions, Ascendant Calculation, Divisional charts, Dasas, transits, etc.

Switching the Ayanamsa can result in major changes in Dasa balance or high level Varga charts like Shastiamsa.