Lahiri or Raman: What Changes in Your Own Chart

AstroMedha computes every chart on the Lahiri ayanamsa. Ayanamsa is the angle between the two ways of numbering the same zodiac. The tropical numbering starts Aries at the March equinox. The sidereal numbering starts Aries against the fixed stars. The two agreed about two thousand years ago and have been pulling apart ever since, because the Earth's axis turns slowly in a circle and drags the equinox backwards through the constellations. Vedic astrology reads the sidereal zodiac, so the ayanamsa for your birth date is subtracted from every planet's tropical position before anything else in the chart is calculated.

Lahiri is not the only published figure for that angle. B. V. Raman used a smaller one, and charts cast on his figure come out different. If you have compared your chart across two sites and found that the lagna, the sign rising on the eastern horizon at the moment of your birth, does not match, or that you are told you are in two different planetary periods, this is almost always why. Whether it touches your chart at all depends on where your own planets sit, and that is settled below by arithmetic you can run yourself.

The gap, measured

Both figures are anchored at 1 January 1900 and grow at the same rate after that.

The difference is 1 degree 26 minutes 47 seconds of arc, or 1.4463 degrees in decimal. Checked on every 1 January from 1900 to 2030 it holds to six decimal places, running from 1.446301280 to 1.446301467 degrees. Both figures use the same precession rate and differ only in where they were pinned, so the gap between them never widens or narrows. Your grandmother's chart and your daughter's chart are affected by exactly the same amount.

Most write-ups of the two put them "half a degree to a degree" apart. The measured figure above is between one and a half and three times that, and the larger number is the one that decides whether a placement crosses a line.

One and a half degrees sounds small next to a thirty-degree sign, and it would be small if a chart were read by distance. A chart is read by boundaries instead. A planet at 29°50' of Cancer and a planet at 0°10' of Leo are twenty arcminutes apart and are read as two unrelated things.

Which way it moves your chart

Raman's ayanamsa is the smaller number, and the ayanamsa is subtracted, so subtracting less leaves more. Every planet, every node and your lagna sit 1°26'47" further along the zodiac under Raman than under Lahiri. All ten move together, by the same amount, in the same direction. Nothing in the chart moves relative to anything else. Only the boundaries the whole set is measured against effectively slide back.

So the entire question is whether any of your ten placements is sitting inside 1°26'47" of the end of the box it is currently in.

The check you can run right now

Three grids run across a Vedic chart at once, and they are independent of each other. A rashi is a thirty-degree sign. A nakshatra is a 13°20' segment of the zodiac, twenty-seven of them, and it is the grid that drives all Vedic timing. A pada is a quarter of a nakshatra, 3°20' wide. A placement can cross one of these boundaries without crossing the others.

Open your chart with degrees showing. The free kundli calculator prints degree-in-sign for all ten placements. Then apply three thresholds:

Anything below those thresholds stays put. Anything at or above them moves forward one box under Raman. That is the whole rule, and it is arithmetic rather than judgement, so you can settle your own case in about ninety seconds.

The three thresholds also explain why the pada is the noisy one. A pada is 3°20' wide, and 1°26'47" is 43% of it, so nearly half of all placements land in a different pada under Raman. A rashi is 30° wide and the same gap is 4.8% of it. The finer the division, the more often a fixed angular disagreement lands on the wrong side of a line.

How often it actually matters

Twenty thousand charts were computed twice each, once on Lahiri and once on Raman, using the same ephemeris code that produces AstroMedha readings. The births were spread evenly across 1950 to 2010, across every minute of the day, and across twelve Indian cities. Every chart carried the full ten: lagna, seven planets, and the two lunar nodes.

Per placement, a rashi change is uncommon and evenly spread:

Read the first table against the second and the shape is clear. Any single placement holds its sign about 95 times out of 100. Ten of them holding at once is a much weaker bet, which is why a third of people find something moved when they compare two sites, and why a fifth find nothing moved and conclude the argument is academic. Both groups are looking at correct charts.

If every placement were spread evenly through its sign, each row of that table would read 4.82%, since 1°26'47" is 4.82% of thirty degrees. Mars comes out at 5.05% and Jupiter at 4.16%, and the gap between them is real rather than sampling noise. Jupiter is the slowest of the visible planets except Saturn and its speed swings the most, so its time is not spread evenly across a sign. Sampled over 40,000 dates between 1950 and 2010, Jupiter sits in the last five degrees of a sign 13.1% of the time and in the tenth-to-fifteenth degree 18.8% of the time, against 16.7% for an evenly spread body. Being near a boundary less often means crossing one less often.

Why your timeline moves far more than your chart wheel

Vimshottari is the 120-year cycle of planetary periods that gives Vedic astrology its dates. A mahadasha is the longest of those periods, running from six years for the Sun to twenty for Venus. An antardasha is a sub-period inside a mahadasha, and a pratyantardasha is a sub-period inside that.

The whole ladder is anchored to one number: how far the Moon had already travelled into its nakshatra at the moment of birth. The nakshatra's ruling planet becomes your first mahadasha lord, and the part of the nakshatra still ahead of the Moon becomes the part of that lord's period you are born into. Move the Moon forward and you are born deeper into the same nakshatra, so less of the first period remains, so the first period ends sooner, so every boundary for the rest of your life arrives sooner.

The Moon moves forward by 1°26'47" under Raman. A nakshatra is 13°20' wide, so that is 10.847% of it. The first period therefore loses 10.847% of that lord's full length, and the entire ladder behind it slides earlier by the same fixed amount:

Across the 20,000 charts the average shift was 529 days. For someone born under a Venus-ruled nakshatra it is 792 days, which is two years and two months, and it applies to every mahadasha boundary from birth to the end of the cycle. That is why the timing disagreement dwarfs the placement disagreement: the same 1°26'47" that has a 4.8% chance of moving a planet's sign has a 100% chance of moving your dates, and by a lot.

There is a second effect on top of it. If the Moon crosses a nakshatra boundary, your first mahadasha lord changes outright, which reorders the whole sequence rather than sliding it. That happens to 10.80% of births.

Put together, here is what the two settings say about where you are today, on 26 August 2026:

Nine people in ten are in a different pratyantardasha depending on which figure their astrologer uses. Two in three are in a different antardasha. One in ten is in a different mahadasha, which is the difference between being told you are seven years into a Ketu period and being told you have just started twenty years of Venus.

Four charts, worked all the way through

Every figure below was computed twice from the same birth data. The right-hand value is what the same moment produces on Raman.

Nothing on the wheel moves, and the dates still move by 22 months

Born 19 August 1991, 12:43 IST, Chennai.

Not one of the ten changes rashi. Not one changes nakshatra. The lagna stays Scorpio in Anuradha, the Moon stays Scorpio in Jyeshtha, the Sun stays Leo in Magha. Only padas move: the lagna from the second quarter of Anuradha to the third, the Moon from the third quarter of Jyeshtha to the fourth. Anyone comparing chart wheels would say the two agree.

The timeline does not agree.

Mercury's full period is seventeen years, so the ladder moves 673 days, one year and ten months, at every rung. On the day this page was computed the two settings put the same person in a Rahu sub-period and a Saturn sub-period respectively. A Rahu sub-period is read for sudden openings and unconventional routes. A Saturn sub-period is read for delay, and for reward that arrives only after the work. Same person, same minute of birth, opposite advice, and the chart wheel that would have flagged the disagreement shows nothing at all.

The lagna flips, and so does the decade

Born 25 January 1985, 19:39 IST, Kochi.

The lagna was eleven arcminutes from the end of Cancer, so it crosses. Under the Cancer reading the Moon is the chart's ruling planet and Jupiter in Capricorn falls in the seventh house, the house of marriage and partnership. Under the Leo reading the Sun rules the chart and the same Jupiter falls in the sixth, the house of work, debt and health. Every one of the other nine placements moves a house along with it. Venus crosses too, from the last degree of Aquarius to the first of Pisces, which moves it out of Saturn's sign and into Jupiter's.

The Moon stays in Uttara Bhadrapada in both, so the first mahadasha lord is Saturn either way. Saturn's period is nineteen years, so the ladder slides 752.8 days:

Today this person is either four-fifths of the way through a seven-year Ketu period, or nine months into a twenty-year Venus period. Those are opposite readings of the same year. The support message that prompted this page put it in five words: lagna et période sont différents. The lagna and the period are different.

The Moon changes nakshatra and the whole ladder reorders

Born 13 September 1971, 19:48 IST, Lucknow.

Not one placement changes rashi. The Moon sits at Gemini 18°58'23" under Lahiri, which is the fourth quarter of Ardra, ruled by Rahu. Under Raman it sits at Gemini 20°25'09", which is the first quarter of Punarvasu, ruled by Jupiter.

That single crossing rewrites the sequence rather than shifting it:

The two ladders happen to land on Ketu at the same moment today, but they got there through different decades. Under Lahiri this person's Saturn period ran 1989 to 2008 and the Mercury period 2008 to 2025. Under Raman the Saturn period ran 1987 to 2006 and Mercury 2006 to 2023. Any reading that dates a past event to a period, which is how a Vedic astrologer checks whether a chart is being read correctly at all, would place the same event under a different planet.

The sign changes but the nakshatra does not

Born 29 March 1973, 05:45 IST, Pune.

The lagna sits at Aquarius 28°42'29" under Lahiri and Pisces 0°09'16" under Raman. It crosses the sign boundary. It stays in Purva Bhadrapada under both, moving only from the third quarter to the fourth.

Both are correct, because Purva Bhadrapada straddles the Aquarius-Pisces line. The twenty-seven nakshatras divide 360 degrees into 13°20' pieces and the twelve signs divide it into 30 degree pieces, and the two grids only line up every 120 degrees. Nine of the twenty-seven nakshatras therefore sit across a sign boundary: Krittika, Mrigashira, Punarvasu, Uttara Phalguni, Chitra, Vishakha, Uttara Ashadha, Dhanishta and Purva Bhadrapada. If two sources have ever given you the same nakshatra and different moon signs, or the same moon sign and different nakshatras, this is the mechanism.

The same disagreement, stated as a clock

Fixing an ayanamsa is not the same kind of act as fixing a birth time, but the two produce comparable errors, and putting them on the same scale is the fastest way to judge how much weight to give the argument.

For the lagna, the ascendant moves through the zodiac at roughly the speed of the Earth's rotation. Measured across 4,000 births, the clock offset that reproduces the Raman lagna from the Lahiri one runs a median of 6.15 minutes, with a range of 4.05 to 6.80 minutes depending on which sign is rising and how far north the birthplace is.

So the choice between the two figures does about as much to your rising sign as being born six minutes earlier. If your birth time came off a hospital record written to the nearest five minutes, the ayanamsa argument and the record's own imprecision are the same size, and neither is worth agonising over on its own.

For the Moon the picture is different. The Moon covers 1°26'47" in about 2.63 hours. Almost nobody's birth time is uncertain by two and a half hours, so here the choice of figure is a much bigger source of disagreement than the clock. That asymmetry is the practical takeaway: the ayanamsa question is a minor question about your rising sign and a major question about your dates.

For the Sun the offset is 1.47 days, which is why people born within about a day and a half of a sign change get a different sun sign from different sites, and everyone else does not.

What it does to transits and to sade sati

A transit is a planet's position now rather than at your birth, and the same 1°26'47" applies to it. A planet reaches a sign boundary earlier under Raman if it is moving forward, and later if it is moving backwards, since Raman's boundaries sit slightly behind Lahiri's from the planet's point of view.

Computed ingress dates, both settings:

Rahu is the clean case, always four weeks and always later, because Rahu is computed as a mean point that travels backwards at a constant rate. Saturn and Jupiter vary between about one and three weeks depending on how fast they happen to be moving when they reach that particular boundary.

Sade sati is the seven-and-a-half-year stretch while Saturn crosses the sign before your Moon's sign, your Moon's sign, and the sign after. Its dates are built out of two things the ayanamsa touches: which rashi your natal Moon is in, and when Saturn enters each of the three. For the 95.24% of people whose natal Moon holds its sign, the whole window shifts by a week or two, which changes nothing about how you would plan around it. For the 4.76% whose natal Moon crosses, the window moves by a full sign, which is two and a half years. The sade sati calculator uses Lahiri, in line with every Indian panchang, the printed almanac that fixes festival and muhurat dates.

Which one is correct

No observation settles it, and it is worth being clear about why rather than leaving the impression that one camp has proof.

The sidereal zodiac needs a zero point, some agreed place among the stars where Aries begins. The classical texts describe that point by naming stars near it rather than by giving a coordinate, and the descriptions do not all reduce to the same coordinate. Every published ayanamsa is one attempt to turn those descriptions into a number.

The most common attempt uses the star Chitra, which is Spica in Virgo, and puts it opposite the start of Aries at exactly 180 degrees. Here is where each figure actually places Spica on 26 August 2026:

Lahiri lands 1'11" short of the Chitra target, close enough that Lahiri is routinely described as the Chitra-based figure. Raman lands 1°25'36" past it, so whatever fixed Raman's zero point, Chitra at 180 degrees was not it. Neither placement can be checked against an event, because no observation says where the zodiac "really" starts. Precession itself is measurable to fractions of an arcsecond. Where the count begins is a decision somebody made.

What can be checked is which decision the rest of Vedic practice is calibrated to. Lahiri is the figure India's Calendar Reform Committee adopted for the national almanac, and it is what Indian panchangs print. Almost every practising Indian astrologer works from a panchang, so Lahiri is the figure your dates have to agree with if you want two readings of your life to line up.

What AstroMedha uses, and why

AstroMedha computes on Lahiri, from the Swiss Ephemeris, with the mean lunar node for Rahu and Ketu and whole-sign houses. That combination is set fresh before every single chart calculation rather than once at startup, so two charts computed at the same moment cannot pick up each other's settings.

Lahiri is the default for one reason that matters more than the astronomy: your chart has to survive contact with everything else you will read. If your dasha dates here match the panchang your family follows and match what a jyotishi in Bengaluru tells you, the readings compound. If they are eighteen months off, you spend your attention reconciling calendars.

There is one deliberate exception, and it is labelled wherever it appears. Krishnamurti Paddhati, a prediction method that works through very fine subdivisions of each nakshatra, is defined on its own ayanamsa and on Placidus house cusps rather than whole signs. Computing a Krishnamurti sub-lord on Lahiri whole-sign houses produces a number that is not a Krishnamurti sub-lord. AstroMedha therefore computes that one block on its own terms, and labels it as a Krishnamurti calculation with its own ayanamsa value wherever it appears. Everything else in your chart, the lagna, the houses, the nakshatras, the dashas and the transits, is Lahiri throughout.

The failure worth avoiding is mixing the two. Reading a Raman lagna against a Lahiri dasha ladder combines halves of two charts that were never meant to be combined, and the result agrees with neither. If you want to see your chart on Raman, see all of it on Raman, dates included.

See it on your own chart

Enter your date, time and place of birth and this page will compute your chart twice, once on each figure, and show you both side by side. What you get:

All ten placements in two columns, with the sidereal longitude to the arcsecond under each figure, and the rashi, nakshatra and pada each one falls in. Anything that crosses a boundary is flagged, so you can see at a glance whether your case is one of the 35.80% where something moves.

Your distance to the nearest boundary, in arcminutes, for every placement. The single most useful number on the page, because it tells you not only whether your chart is affected today but how close it came. A Moon at 11°50' into its nakshatra is three arcminutes from a different first mahadasha lord, and that is worth knowing before you take any dasha date literally.

Both Vimshottari ladders in full, from birth to the end of the 120-year cycle, with the exact shift in days between them, and your mahadasha, antardasha and pratyantardasha under each figure as of today.

A plain verdict, in a sentence: whether the choice of figure changes your reading, and which part of it.

The chart you can already build free without this comparison is the full kundli, which gives your placements, houses and degrees on Lahiri. The dasha calculator gives the Lahiri ladder with dates, and the nakshatra finder gives your birth star with its pada.