Trimsamsa Chart Calculator (D30)

The D30 is read for where a chart is exposed. Classical practice used it for arishta — misfortune of the kind that arrives rather than the kind that is chosen — and for the qualities of character that surface under pressure. It is one of the two vargas traditionally read differently for men and for women, a convention this page notes and does not apply, because the reasoning behind it does not survive examination.

Because only the five non-luminous planets rule Trimsamsas, the reading is naturally organised around them. Mars and Saturn bands are read as the harsher exposures — impulse and attrition respectively — and Jupiter, Mercury and Venus bands as the milder ones. That is a description of the flavour of a vulnerability, not a grading of how bad it is.

A useful cross-check: the ruler of the Trimsamsa a planet falls in is often more informative than the resulting sign. The result panel above names both, because the band ruler is the classical reading and the rashi is what a chart drawing needs.

This varga has no divisor. In an odd sign the five bands are Mars 0-5 degrees, Saturn 5-10, Jupiter 10-18, Mercury 18-25 and Venus 25-30; in an even sign the same rulers appear in reverse with different widths — Venus 0-5, Mercury 5-12, Jupiter 12-20, Saturn 20-25 and Mars 25-30. The planet lands in that ruler's own rashi: the odd one of the pair in odd signs and the even one in even signs. The Sun and Moon own no Trimsamsa, so **Cancer and Leo can never appear in a correctly computed D30**.

That rule is the whole difference between a divisional chart and a decorative second drawing of the birth chart. The start sign — which sign the parts are counted from — is fixed per varga by classical text and is not the cyclic multiplication most calculators use. The two agree only for divisors 16, 20 and 27.

Parashara gives the Trimsamsa bands in the sixth chapter of the Brihat Parashara Hora Shastra and assigns the varga to arishta — misfortune, and by extension to the character that shows when things go wrong. Sanjay Rath's published treatment of the same bands is the reference the engine's implementation cites.

The unequal widths are the whole point and the reason a generic divisor cannot compute this chart. Dividing a sign by thirty and taking one-degree parts produces a plausible-looking D30 that is wrong for every degree of every sign. The engine keeps the bands in ``divisional_charts._TRIMSAMSA_ODD_BANDS`` and ``_TRIMSAMSA_EVEN_BANDS`` and routes both the chart and the prose through the same function, which is what stops the two halves of one page from disagreeing.

1. Read the band ruler before the sign The classical Trimsamsa reading is by ruler: which of Mars, Saturn, Jupiter, Mercury or Venus owns the band a planet falls in. The rashi that results is how the chart is drawn; the ruler is what the text is talking about.
2. Read the ascendant's Trimsamsa first The lagna's band describes the exposure of the whole chart rather than of one theme, and it is where classical readings of this varga begin.
3. Read the Moon's Trimsamsa for the mind under pressure The lunar band is the specific line about how a person responds when strained, as distinct from how they behave when they are not. It is the most practically useful placement in the chart.
4. Check for Cancer or Leo, and distrust the chart if you find them The luminaries own no Trimsamsa, so those two signs cannot appear. If a D30 from anywhere shows a planet in Cancer or Leo, that tool has applied an equal thirty-part division instead of the classical bands, and every placement in it is suspect.
5. Read it as exposure, never as fate Arishta in the classical sense means a vulnerability, not a sentence. The whole value of knowing where a chart is thin is that it can be attended to; a reading that presents it as fixed has removed the only useful thing about the varga.

A planet occupying the same sign in the birth chart and in the D30 is vargottama in this division — literally 'best in division'. The reading is stability rather than strength: the planet is doing the same thing at two resolutions of one chart, so whatever it signifies is consistent rather than conditional. The result table above marks them.

Two cautions. A consistently difficult placement is also vargottama, and the reading is then that the difficulty is stable. And in the D12 and the D60 the division counts from the sign itself, so a planet at the very start of a sign is vargottama by construction rather than by merit — a property of the rule and not a dignity. The vargottama calculator checks every planet against every division at once.

A wrong divisional chart does not look wrong. It renders cleanly, it is internally consistent, and nothing warns you — which is why the same three mistakes have propagated across the internet for twenty years. All three come from computing a varga with arithmetic instead of with its classical rule.

The cyclic shortcut. Multiplying the sign index by the divisor and taking the result modulo twelve is a tempting one-liner and it agrees with Parashara only for divisors 16, 20 and 27. For 12 and 60 it always yields a multiple of twelve — Aries — so it discards the planet's own sign and puts an entire chart in one sign. A D12 or D60 in which every planet shares a sign is this bug, and it is common enough that most readers have seen one without recognising it.

The missing odd-even reversal. The D7 counts from the 7th sign in an even sign and the D10 from the 9th. A generic divisor ignores both, which displaces every even-sign planet by six signs in a D7 and eight in a D10 — roughly half the chart, moved half the zodiac, with no symptom at all.

Treating the D30 as an equal division. The Trimsamsa has five unequal bands per sign, reversed in even signs. Dividing by thirty instead produces a chart that is wrong at every degree of every sign, and one that shows planets in Cancer or Leo — signs a real Trimsamsa cannot contain.

The check for this varga: Cancer and Leo can never appear, because the Sun and Moon own no Trimsamsa band. If a D30 you have been given anywhere fails that test, the start-sign rule was not applied and every placement in it is suspect.

The start-sign rules this site uses are stated in the engine and pinned by a test against a hand-derived chart, with a published citation for each of the sixteen. That is not a claim of infallibility; it is a claim that the rules are written down where they can be checked, which is the only kind of claim a calculator can honestly make.

The Trimsamsa bands are unequal — five, seven, eight and five degrees wide depending on the sign's parity and the band. The ascendant moves through roughly one degree every four minutes of clock time, so the D30 ascendant holds for about 20 to 32 minutes before it changes sign. That figure is an average: the rate varies with latitude and with which sign is rising, and near the poles it varies a great deal.

Planets are far steadier than the ascendant, which is why a rounded birth time damages a divisional chart unevenly rather than uniformly. The Moon is the fastest of them and changes Trimsamsa about every 9 to 15 hours; the Sun takes around a month per sign in the birth chart and correspondingly longer per division; Jupiter and Saturn are effectively fixed across a whole day. So if your recorded time is uncertain, distrust the ascendant first and the Moon second, and read the slow planets with confidence.

This page assumes a rectified birth time — a time established or confirmed against events, rather than one recalled to the nearest quarter hour. Every divisional chart beyond the D9 is highly sensitive to birth time, and the finer ones are not merely less reliable on a rounded time but arbitrary: at half a degree per division the D60 ascendant changes about every two minutes, so a time rounded to five minutes leaves two or three equally likely charts and no way to choose between them. If you do not have a time you trust, the honest thing is to read the birth chart and the Navamsa and stop there.

The ascendant is not a property of the instant alone. It is the point of the ecliptic rising over a particular horizon, so it is a function of the moment and of the coordinate together, and the two trade off exactly: the sky turns one degree every four minutes, and one degree of longitude is four minutes of local time. Moving five to eight degrees of longitude — about 516 to 826 km east or west at Indian latitudes — moves the ascendant by one whole Trimsamsa part, which is to say it hands you a different D30 ascendant and rotates every house in the chart above.

Latitude matters separately and less obviously. It does not shift the clock, it changes how fast each sign climbs — the ascensional difference — so two places on the same meridian and the same instant still rise different degrees, and the gap grows the further from the equator you are. This is why a chart cast for a state capital is not a rounding of a chart cast for a village two districts away; it is a different chart that happens to look plausible.

So enter the town you were actually born in. The place search above accepts any village, town or city a geocoder knows, not a shortlist of metros, and it prints the latitude, longitude and timezone it used above the result so you can check them against a map. Since a D30 division is the unit this page is built from, a birth place picked for convenience damages the result in the same way and by the same mechanism as a birth time rounded to the nearest quarter hour.

The Trimsamsa does not predict misfortune, accident, illness or loss. It describes where a chart is exposed. Anyone selling a remedy on the strength of a D30 is selling fear, and this site sells neither.

The classical convention of reading this varga differently for men and women is noted here as history and not applied. The reasoning behind it does not survive examination and the results it produced were used badly.

Nothing in this chart is a medical or safety statement. If you are worried about your health or your safety, the answer is a doctor or the appropriate service, immediately, and not a chart.

Two limits apply to every page in this family and are worth stating in one place. Divisional charts beyond the D9 are highly birth-time sensitive, and every reading here assumes a rectified birth time. And nothing on this site is medical, legal or financial advice: a chart is a traditional interpretive framework, not a diagnosis, not a forecast, and never a reason to delay professional help.

Parashara's sixteen divisions are a single instrument, not sixteen instruments. The birth chart is cut at sixteen different resolutions — halves, thirds, quarters, sevenths, ninths, tenths, twelfths, sixteenths, twentieths, twenty-fourths, twenty-sevenths, thirtieths, fortieths, forty-fifths and sixtieths — and a planet's condition is judged from how it behaves across them rather than from any one. The D30 is one of those sixteen and is read in that company.

The weighting is called Vimshopaka Bala, twenty-point strength, and it is where the tradition states which divisions carry most. D1, D9 and D60 take the largest shares; the D2, D3, D7, D10 and D12 sit in the middle; the D16, D20, D24, D27, D40 and D45 carry least. That ordering is worth respecting. A reading built on a minor varga against the evidence of the major ones is almost always reading a birth-time error.

Two of the sixteen are not equal divisions and must never be computed with a generic divisor. The D30 Trimsamsa has five unequal bands per sign, reversed in even signs. The D60 Shashtiamsa is an equal division for the rashi but its sixty deities are enumerated forwards in odd signs and backwards in even ones. Beyond those, the start-sign rule differs per varga and only coincides with the cyclic shortcut for divisors 16, 20 and 27 — for 12 and 60 the shortcut collapses the whole chart into Aries. Every chart on this site uses the classical rules, which are pinned by a test against a hand-derived chart.

D8 Ashtamsa and D11 Rudramsa are deliberately absent from this engine and from this site. They are not part of Parashara's sixteen, and the published rules for them disagree with each other, so there is no single chart to compute. Publishing one would mean choosing a rule and not saying so.