Ayanamsa
Why one planet can change sign alone
A different ayanamsa shifts every planet by the same small amount, yet often only one changes sign. See why closeness to a boundary decides it.
01 · One chart, one offset
An ayanamsa change shifts every body equally; only one may cross a line.
Changing the ayanamsa moves every sidereal longitude by the same small amount. Whether a body changes sign depends only on how close it already sits to a sign boundary. Shift this real chart and watch which body crosses first.
02 · Smaller divisions
The finer the division, the nearer the next boundary.
Signs are 30° wide, nakshatras 13°20′, navamsas and padas 3°20′. A body can be far from every sign boundary and still close to a pada or navamsa boundary.
Every body moves by the same amount
The sidereal longitude of a planet is its tropical longitude minus the ayanamsa. Changing the ayanamsa therefore moves every sidereal position in a chart by exactly the same amount, in the same direction. Raising the ayanamsa by 7′ lowers every planet, the ascendant and the nodes by 7′.
A sign changes only if that shift carries a position across a sign boundary. A planet 10° inside its sign ignores a change of a few arcminutes; a planet a few arcminutes inside its sign does not.
One chart
For 06:00 IST on 1 November 2026 in Delhi, on the site’s True Chitrapaksha reference, Jupiter is just 6½′ into Leo. Every other body, and the ascendant, is at least a degree and three-quarters from a sign boundary: Rahu is 1°51′ into Capricorn and Venus 2°01′ into Libra.
- Raise the ayanamsa by 7′ and Jupiter moves into Cancer. Nothing else changes sign.
- Raise it by 2° and Rahu also moves back a sign, while Venus, just over 2° in, stays.
- Lower it, as the KP reference does by about 4½′, and Jupiter moves further into Leo.
The Lahiri formula is about 0.9′ above True Chitrapaksha, too little to move Jupiter across.
Smaller divisions, nearer boundaries
Signs are 30° wide, but a chart also uses smaller divisions: nakshatras of 13°20′, and padas and navamsas of 3°20′. The smaller the division, the closer its nearest boundary usually is. In the same chart the Moon is more than 3½° from any sign boundary, but only 12.8′ inside Pushya nakshatra, and the ascendant is 13.5′ from the next nakshatra.
That matters beyond the label. The Moon’s nakshatra at birth sets the first period of the Vimshottari dasha; a 13′ rise in the ayanamsa would move this Moon into Punarvasu and change the first dasha from Saturn’s to Jupiter’s.
Reading a borderline chart
When a chart has a body within a few arcminutes of a boundary, its label for that division depends on small choices: the ayanamsa, and also the birth time, since the Moon moves about half a degree an hour. What an ayanamsa change does to a chart shows how often that happens, and the ayanamsa guide explains the choices the Kundli page offers.
Try the ayanamsa selector on the Kundli page, or explore another topic in Learn.