Ayanamsha: Lahiri, Raman, KP and others

Where the ayanamsha comes from

Earth's axis slowly traces a cone, and the spring equinox slides against the stars by about one degree every 72 years — this is precession. The tropical zodiac is tied to the equinox and drifts away from the constellations; the sidereal zodiac is tied to the stars. The angle between their starting points is the ayanamsha (Sanskrit ayana, movement, and amsha, portion). By Lahiri it was zero around the end of the 3rd century CE; in 2026 it is 24°13′. More on the two zodiacs in why my Vedic sign is different.

Why there are several ayanamshas

The rate of precession is known precisely; what is debated is where the sidereal zodiac starts — in which year the angle was zero. Classical texts name nakshatras and stars but give no unambiguous starting point in modern coordinates. So each school chose its own reference star or date.

The main ayanamshas and their values

Values for 1 July 2026.

Lahiri: why it became the standard

In 1955 India's Calendar Reform Committee, chaired by the astrophysicist Meghnad Saha, adopted the ayanamsha proposed by N. C. Lahiri: the star Spica (the nakshatra Chitra) stands at exactly 0° Libra. Since then it has been used by the official Indian ephemeris and by most panchangs, programs and astrologers. That does not prove Lahiri is “the true one”, but it gives a common language: the date of Ekadashi, the nakshatra in the panchang and your chart are all calculated the same way.

Raman, KP, Pushya-paksha

Raman. B. V. Raman, one of the most influential astrologers of the 20th century, used his own ayanamsha, and readers of his books still choose it. It is a degree and a half smaller than Lahiri, so for some people the Moon and lagna move into the neighbouring nakshatra.

KP. In the Krishnamurti system each nakshatra is split into unequal “subs”, and the exact degree becomes decisive. The KP ayanamsha differs from Lahiri by only 6′, but KP practitioners use nothing else — the rules were tuned to it.

Pushya-paksha. P. V. R. Narasimha Rao, the author of Jagannatha Hora, proposed counting from the yogatara of the nakshatra Pushya. Its supporters consider it more accurate for dashas; this is the view of some modern researchers, not a classical standard.

How the ayanamsha changes a chart

Signs. A 1.5° difference changes a planet's sign only near the edge of a sign: for the Moon that is about one person in twenty. Nakshatras. A nakshatra is a third the width of a sign (13°20′), so with Raman instead of Lahiri the Moon lands in the neighbouring nakshatra for about one person in nine. Dashas. The balance of the first dasha is proportional to the Moon's path inside its nakshatra: with the Moon in a Venus nakshatra, one arc-minute is about 9 days; in a Sun nakshatra about 3 days. So even the 6′ between Lahiri and KP shift every date by almost two months.

Which ayanamsha to choose

The rule is simple: use the one your interpretive rules were written for. Classical Parashari astrology and Indian panchangs — Lahiri. KP — KP only. If you learned from Raman's books — Raman. Do not choose an ayanamsha by which chart you “like” better: that is fitting, not testing. Testing an ayanamsha on your own chart makes sense only against the dates of real events and only within one school.

What JyotiSoft uses

JyotiSoft calculates with the Lahiri ayanamsha — the same as the Indian ephemeris and panchangs, so the dates in the calendar and in your chart agree. If two programs show you different things, start with why programs show different charts: the ayanamsha is only one of seven causes.

Questions

See also

• Why my sign is different
• Why programs show different charts
• Vimshottari dasha
• Chitra
• Pushya
• KP and the Parashari school

Positions and tables: sidereal zodiac, Lahiri ayanamsha — the same as professional Jyotish astrologers use, and the same calculation as the charts in JyotiSoft. Updated 2026-10-14.