Ayanamsa Comparison: Lahiri, KP, Raman and True Chitrapaksha

Enter a date, a time and a town above, and this free tool gives the four ayanamsas most used in Vedic astrology at that moment: Lahiri, KP (Krishnamurti), Raman and True Chitrapaksha. It shows how far each is from Lahiri, then the sign, degree, nakshatra and pada of the Lagna and the nine grahas under each one, and marks every place where a different ayanamsa would change the sign, the nakshatra or the pada. Use a birth date and time to see whether the choice of ayanamsa matters for a chart.

What an ayanamsa is

Vedic astrology measures the planets in the sidereal zodiac, which stays fixed against the stars. The tropical zodiac of Western astrology starts from the spring equinox, which slides slowly backwards against the stars. The ayanamsa is the distance between the two starting points on a given date, and a sidereal position is the tropical position less the ayanamsa. Astronomers agree on the tropical positions; the schools of astrology differ on where the sidereal zodiac begins, and so on the ayanamsa.

How it works

The tool reads the four ayanamsas from the tables behind every chart on this site, made from NASA JPL DE440. Lahiri is held for every date from 1900 to 2074; KP, Raman and True Chitrapaksha are held from 1950 and offered from 1 January 1951, 0:00 Universal Time. Each value is the true ayanamsa, with nutation, the form in which the Indian Astronomical Ephemeris gives Lahiri. For the positions, the tool takes the tropical position of each graha and of the Lagna at your moment and place, and subtracts each ayanamsa in turn. Rahu is the mean node.

How each ayanamsa is defined follows the documentation of the Swiss Ephemeris (section 2.8), the independent program our checks use, which cites the original books:

• Lahiri (Chitrapaksha): the Indian standard since the Indian Calendar Reform Committee of 1955, with the Indian Astronomical Ephemeris value of 23° 15′ 00.658″ on 21 March 1956. This site uses it everywhere.
• KP (Krishnamurti): the ayanamsa of K. S. Krishnamurti’s KP system, in the form that fits the table of values in his KP Reader 1 (pages 54 to 59).
• Raman: the ayanamsa of B. V. Raman, who gives its zero year as 389 CE in Hindu Predictive Astrology (pages 378 to 379).
• True Chitrapaksha: keeps the star Chitra (Spica) at exactly 180°, the start of Tula, on every date, so it follows the star’s own small motion.

We checked the tool against the Swiss Ephemeris for each of the four at 318 moments from 1900 to 2074: the ayanamsas agree to 0.15 arcsecond, the grahas to 3.6 arcseconds and the Lagna to 7.3 arcseconds, and not one sign, nakshatra or pada came out differently. The accuracy page has the method and the Lahiri test set.

Reading the result

On 1 January at 0:00 Universal Time, our tables give these values, cut to the second:

At every moment we checked from 1951 to 2074, every six hours, KP is 5′ 48″ less than Lahiri and Raman is 1° 26′ 46″ less. The True Chitrapaksha gap is not fixed: it changes through the year, and over those years it runs from 33″ to 1′ 20″ less than Lahiri, though on the 1 January dates in the table above it stays between 59″ and 1′ 04″. So KP and True Chitrapaksha change a chart only for a planet or Lagna very close to the edge of a sign, nakshatra or pada, while Raman, almost a degree and a half apart, changes the pada more often and sometimes the nakshatra or the sign. The last column of the second table says exactly what changes for your moment.

Where traditions differ

Lahiri is the ayanamsa of the Government of India’s Rashtriya Panchang, and this site uses it. KP astrologers use the KP ayanamsa, and astrologers who follow B. V. Raman’s books use his. Some astrologers prefer a true star-based ayanamsa such as True Chitrapaksha. There are other ayanamsas still, such as Fagan-Bradley and Yukteshwar, both in the Swiss Ephemeris list, which this tool does not include. None of these is a matter of measurement error: each is a choice of where the zodiac begins, and a chart should be read with the ayanamsa its system was built on.

What it does not do

It does not change the other calculators on this site, which all use Lahiri; the transits page can show the planets now with any of these four. Before 1951 it gives Lahiri only. It does not cover the tropical zodiac as a choice of its own, though a tropical position is the Lahiri position plus the Lahiri value shown. For a month of Lahiri positions, see the monthly ephemeris table.

Frequently asked questions