What is the ayanamsa? Lahiri, Raman and KP compared
The ayanamsa is the angle between the tropical and sidereal zodiacs: how far the spring equinox has drifted from the sidereal starting point. Every Vedic position is a tropical position minus the ayanamsa, so the choice of ayanamsa decides signs near a boundary, nakshatras and dasha dates.
1. Foundations · lesson 3 of 10
Key points
- Ayanamsa (अयनांश) means 'the portion of the ayana', the accumulated precession of the equinox.
- It grows by about 50.3″ a year; in 2026 the Lahiri value is about 24°13′.
- Different ayanamsas place the sidereal zero point differently; Lahiri, Raman and KP are the three most used in India.
- Lahiri (Chitrapaksha) sets the star Chitra (Spica) at 0° Libra; it was recommended by the Government of India's Calendar Reform Committee in 1955.
- KP differs from Lahiri by only about 6′; Raman differs by about 1°27′, enough to change signs, nakshatras and dasha dates.
- Choose one ayanamsa and use it consistently; mixing them makes comparisons meaningless.
The idea in one sentence
The tropical zodiac starts at the vernal equinox, which drifts; the sidereal zodiac starts at a point fixed to the stars. The ayanamsa is the distance between the two starting points on a given date. Because the equinox moves westward by about 50.3″ a year, the ayanamsa grows by that amount each year.
Sidereal position = tropical position − ayanamsa.
Why there is more than one ayanamsa
Everyone agrees on the rate of drift; the disagreement is about the zero year, the moment when the two zodiacs coincided, which fixes where sidereal 0° Aries lies. The classical texts do not give a single unambiguous star reference, so different scholars chose different anchors.
| Ayanamsa | How it is defined | Value at 1 Jan 2000 | Value in 2026 (approx.) |
|---|---|---|---|
| Lahiri (Chitrapaksha) | The star Chitra (Spica) at exactly 180° (0° Libra) | 23°51′ | 24°13′ |
| Krishnamurti (KP) | Close to Lahiri; defined for the KP system by K. S. Krishnamurti | 23°46′ | 24°07′ |
| Raman | Defined by B. V. Raman, zero year around 397 CE | 22°25′ | 22°46′ |
These are the values this site uses (see the method page). Other ayanamsas exist, such as Fagan-Bradley in Western sidereal astrology and Yukteshwar, but they are rarely used in Indian practice.
How big the differences are in practice
A difference of a degree sounds small, but Jyotish divides the zodiac finely. A nakshatra is only 13°20′ and a pada 3°20′; a navamsha is 3°20′ as well. So:
- Lahiri vs KP (about 6′): almost never changes a sign; can change a sub-lord in KP and shift dasha dates by a few weeks.
- Lahiri vs Raman (about 1°27′): changes the sign of any planet within 1°27′ of a sign boundary, often changes the nakshatra pada, and shifts the Vimshottari dasha timeline by up to a few years.
Worked example: why the dasha moves
The Moon moves through a nakshatra (13°20′) in about one day, and the dasha balance at birth depends on how much of the nakshatra is left. Moving the Moon back by 1°27′ (Raman instead of Lahiri) changes the fraction left by 1°27′ ÷ 13°20′ ≈ 11%. If the first dasha is Venus (20 years), the dates of the whole timeline shift by about 11% of 20 years, roughly 2 years and 2 months.
That is why a chart should always state its ayanamsa, and why two astrologers can disagree on a dasha date with the same birth data.
Which one should you use?
Lahiri is the default almost everywhere in India: it is the official ayanamsa of the Indian Ephemeris and most printed panchangs, so festival dates and sankrantis in Indian calendars use it. Use Lahiri unless you have a reason not to.
KP is used with the Krishnamurti Paddhati system, whose sub-lords are sensitive to small differences; use it when following KP methods. Raman is used by followers of B. V. Raman's school.
Whatever you choose, keep it consistent across charts you compare, and note it when you share a chart.
How this site computes it
The site starts from the published value of each ayanamsa at the J2000 epoch (1 January 2000, 12:00 TT) and adds the precession of 5,027.8″ per Julian century (about 50.28″ a year) for the date in question. Lahiri on this basis agrees with published Indian ephemerides to within seconds of arc, and the resulting planetary positions match Drik Panchang to within about 30″.
Common mistakes
- Comparing a chart made with Raman to one made with Lahiri and concluding one 'has the wrong Moon sign'.
- Assuming the ayanamsa is a fixed 23° or 24°; it changes every year.
- Using an online chart without checking which ayanamsa it uses; many Western tools default to tropical.
- Switching ayanamsa to get a 'better' result. Pick one for reasons of method, not outcome.
See it on your chart
Every tool on this site has an Ayanamsa selector with Lahiri, Raman and KP. Make your Kundli once with Lahiri, then switch to Raman and watch the planets near sign boundaries, the nakshatra padas and the dasha dates move. The value used is printed in the report header.
Questions and answers
What is the ayanamsa today?
About 24°13′ with Lahiri in 2026; it grows by about 50″ a year.
Is Chitrapaksha the same as Lahiri?
Yes. 'Chitrapaksha' refers to the anchor, the star Chitra (Spica) at 0° Libra; N. C. Lahiri's computation of it was adopted by the Calendar Reform Committee.
Does the ayanamsa affect the tithi?
No. A tithi depends only on the angle between the Moon and the Sun, which is the same in both zodiacs. The nakshatra, yoga and every sign do depend on it.
Report of the Calendar Reform Committee (1955) and the Indian Astronomical Ephemeris; B. V. Raman, A Manual of Hindu Astrology; K. S. Krishnamurti, KP Reader I; J2000 reference values as listed in the Swiss Ephemeris documentation. Precession rate from the IAU 2006 model.