Choose your ayanāṁśa
Ayanāṁśa is the changing offset between tropical and sidereal zodiacs. Mạghā offers 21 Swiss Ephemeris ayanāṁśas, with Lahiri as the default, plus tropical mode. The choice changes sidereal positions, so keep it consistent when comparing charts.
Two zodiac rings turned 23°47′ apart, the Lahiri value for the chart birth on 14 October 1994. One marker shows the Moon at 18°02′ Aquarius on the tropical ring and 24°15′ Capricorn on the sidereal ring.
| Frame | Moon |
|---|---|
| Tropical · outer ring | 18°02′ Aquarius |
| Sidereal Lahiri · inner ring | 24°15′ Capricorn |
| Ayanāṁśa | 23°47′ |
Lahiri comes from India's 1955 calendar reform
India's Calendar Reform Committee, led by Meghnad Saha with N. C. Lahiri as secretary, fixed 23°15′00″ for 21 March 1956 in its 1955 report, following the Chitrā tradition. Mạghā's default Lahiri uses the 1985 revision, 0.658″ higher; Lahiri ICRC retains the committee value. Lahiri 1940 follows Panchanga Darpan, and VP285 sets zero at the 285 CE equinox. The sample's 23°47′ offset moves its tropical Aquarius Moon to sidereal Capricorn.
KP has its own ayanāṁśa
Krishnamurti placed the zero ayanāṁśa in 291 CE without an exact date. Mạghā offers Krishnamurti (KP), based on his table, and KP VP291, fixed to 21 March 291. In this calculation they lie 5′49″ and 4′36″ below Lahiri respectively.
KP charts always use sidereal Krishnamurti (KP), independently of the main chart’s zodiac and ayanāṁśa settings.
Raman's ayanāṁśa is 1°27′ smaller than Lahiri's
B. V. Raman (1912–1998) used his own ayanāṁśa in books such as Hindu Predictive Astrology. The Swiss Ephemeris documentation, citing K. Chandra Hari, traces it to the 12th-century astronomer Bhāskara II, who assumed an ayanāṁśa of 11° in 1183.
For the chart birth, Mạghā's engine records Lahiri at 23°47′ and Raman at 22°20′, a gap of 1°27′. A smaller ayanāṁśa moves every sidereal position forward by the difference. Under Raman, any planet in the last 1°27′ of a sign by Lahiri moves into the next sign, and the Moon advances about 11% of the way through its 13°20′ lunar mansion (nakṣatra). That changes the dates of the 120-year planetary period system (Vimśottarī Daśā). The last section of this page works through that change for the sample.
Four True options pin one star to a fixed degree
Most ayanāṁśas fix a value on one date and add a steady rate of precession, so the star they began from can drift slightly over the centuries. The four options labelled True recalculate the offset at every moment so that one star stays exactly where its tradition puts it.
True Citra keeps Chitrā (Spica) at 180°, the start of Libra, which is the Chitrapakṣa rule applied exactly. True Revati keeps Revatī (zeta Piscium) at 359°50′, ten minutes of arc before the end of Pisces. True Pushya keeps Puṣya (delta Cancri) at 106°, or 16° Cancer; P. V. R. Narasimha Rao, who proposed it, regards that star as the best anchor for the sidereal zodiac. True Mula, proposed by K. Chandra Hari, keeps Mūla (lambda Scorpii) at 240°, the start of Sagittarius.
Eight options go back to Āryabhaṭa and the Sūrya Siddhānta
Surya Siddhanta and Aryabhata use their respective timings for the 499 CE equinox. Their Mean Sun variants use the modern mean Sun then, about 13–14′ away. Aryabhata 522 follows Govindasvāmin's reported epoch. SS Revati and SS Citra fix the text's polar longitudes at 359°50′ and 180° in 499 CE.
Yukteshwar is Swiss Ephemeris's Graham Dawson version. The Holy Science gives 20°54′36″ for 1894 at 54″ yearly; this option gives about 21°00′ and uses modern precession.
Fagan/Bradley and Ushashashi follow Babylonian and Greek reference stars
Fagan/Bradley comes from Western sidereal astrology. Around 1950 the astrologer Cyril Fagan argued that the zodiac of ancient Babylon was sidereal, with the star Spica near 29° Virgo, and Donald Bradley derived the exact value from Spica at 29°06′05″ Virgo. Choose it when you want a chart in the Western sidereal convention.
Ushashashi starts the zodiac near the star Revatī. The historian Raymond Mercier found that Greek and medieval Arabic tables share a zero point 10 to 22 minutes of arc east of Revatī (zeta Piscium), which he attributed to the astronomer Hipparchus. Ushashashi uses the same zero point, about 10 minutes of arc east of Revatī, and differs from the Hipparchan ayanāṁśa by 11 minutes.
Tropical mode switches the ayanāṁśa off
The tropical (sāyana) zodiac, which Western astrology uses, measures every position from the March equinox, so it needs no ayanāṁśa. Set “Zodiac mode” to Tropical and Mạghā calculates planets and houses in that frame. The “Ayanamsa” list switches off with the note “Ayanamsa is off in Tropical mode.”
With a gap near 24°, any position more than 6° into a sidereal sign lies in the next sign tropically. That covers four positions in five, which is why a Western Sun sign is usually one sign later than the Vedic one. In the chart, the Sun is at 26°40′ Virgo sidereally and 20°28′ Libra tropically.
Changing the ayanāṁśa moves every Vimśottarī date
Changing ayanāṁśa shifts every sidereal position equally. Signs and nakṣatras change near boundaries; smaller divisions change more readily, since D9 spans 3°20′ and D60 only 0°30′. The Moon's progress and Vimśottarī dates shift too: Raman moves Nila's Moon from 0°55′ to 2°22′ into Dhaniṣṭhā, starting later periods about nine months earlier. Use your tradition's setting when comparing. Daily Pañchāṅga always uses Lahiri independently.
Common questions about choosing an ayanāṁśa
Which ayanāṁśa is most accurate?
None can be proved right by astronomy alone. Astronomy fixes where the equinox and each star lie to a fraction of a second of arc; the open question is which reference point should start the sidereal zodiac.
Lahiri is the standard India's Calendar Reform Committee set in 1955 and Mạghā's default, and KP work uses Krishnamurti's value. Use the one your method was built on.
What does “Ayanamsa: Lahiri” mean on my kundli?
It means the chart was calculated in the sidereal zodiac, after subtracting the Lahiri ayanāṁśa from each position measured from the equinox. That value was 23°47′ for a birth in October 1994 and 24°14′ in September 2026. A kundli made with another ayanāṁśa shows degrees that differ by minutes to almost 4°, and occasionally a different sign or nakṣatra.
Lahiri or KP: which chart is right when a planet changes house?
Use the chart that matches the method you are applying. When a planet sits in a different house in the KP chart, the usual cause is KP's Placidus cusps, not the ayanāṁśa: Lahiri and Krishnamurti (KP) are only about 6 minutes of arc apart, so the ayanāṁśa alone moves a planet only when it lies that close to a sign's edge.
KP astrologers read KP charts with Krishnamurti's value, and Mạghā's KP reader always does.
Does changing the ayanāṁśa change my nakṣatra?
Only if the Moon sits near the edge of one. Each nakṣatra spans 13°20′, so moving from Lahiri to Raman changes the birth nakṣatra only when the Moon is within 1°27′ of the next one, about one chart in nine. The Moon's place inside its nakṣatra always changes, so Vimśottarī dates shift even when the nakṣatra stays the same.
Choose your ayanāṁśa in Mạghā
Review your zodiac and ayanāṁśa in Calculation defaults. Lahiri is the default. The demo's chart remains in Lahiri and does not show recalculation with another option.
Open Calculation defaults