D20 Vimshamsa Chart: Twenty Parts and One Long Count

The Vimshamsha cuts each sign into twenty arcs of a degree and a half. Its starting rule looks like an arbitrary list of three signs, and it is easy to mix up with the D16’s, which uses the same three signs in a different order. The order is not arbitrary. Worked through below, it is exactly what makes all 240 D20 parts of the zodiac one continuous count from Aries, and almost every other property of the chart drops out of that.

D20 Chart in Astrology: the Vimshamsha (विंशांश)

Vimsha is twenty; the Vimshamsha (also spelled Vimsamsa, and विंशांश कुंडली in Hindi) is the chart of twentieth parts, each 1°30′ wide. The Parashari list of sixteen divisional charts gives it the entry “worship (upasana)”, an entry no other chart in that list shares; the one after it, the D24, is listed for learning (vidya). That list entry is reported here as the tradition’s, and the page attaches no deity, practice or path to any D20 sign. What it does is the construction. For the full set of sixteen, see the shodashvarga hub.

The Rule: Aries, Sagittarius, Leo

A movable sign (Aries, Cancer, Libra and Capricorn) starts its twenty parts at Aries. A fixed sign (Taurus, Leo, Scorpio and Aquarius) starts at Sagittarius. A dual sign (Gemini, Virgo, Sagittarius and Pisces) starts at Leo. Each later part is the following sign. Since the start depends on mobility alone, the four signs of a group have the same twenty-part row, and the whole 12 by 20 table fits in three columns:

Why Fixed and Dual Are the Other Way Round From the D16

In the D16 a fixed sign starts at Leo and a dual sign at Sagittarius; the D20 has them exchanged. The reason is the remainder. Twenty parts are one round of twelve signs and eight more, so Aries’s count ends on Scorpio and the next sign, Taurus, has to take up the count at Sagittarius. Taurus in turn ends on Cancer, handing Gemini Leo, and Gemini ends on Pisces, handing Cancer Aries and starting the cycle again. In general a sign’s first part sits eight signs further on than the previous sign’s. With sixteen parts the leftover is four instead of eight, and moving four signs forward lands where moving eight lands going backward, so the same three starting signs come up in reverse order.

Is the D20 One Unbroken Chain? Yes: Twenty Rounds

Put the claim as a test. Number every D20 part of the zodiac from 0 at 0° Aries up to 239 at the end of Pisces. If the D20 sign of every part k is k signs on from Aries (counting past Pisces back to Aries as often as needed), the chart is one chain, as the navamsa is. All 240 parts pass. So the zodiac carries twenty complete rounds of the twelve signs, each covering 18°, and five of those rounds fill a quarter of the zodiac exactly, which is why Aries, Cancer, Libra and Capricorn, a quarter apart, read the same. One more consequence: at all twelve sign boundaries the D20 sign just moves on to the next sign, the same as it does between two parts inside a sign. A graha at 29°10′ Gemini is in Gemini’s last part, Pisces; a little further on, at 0°20′ Cancer, it is in Cancer’s first part, Aries, the next sign of the count.

Each Sign Starts on a Different House

Count the first D20 part’s sign from the sign itself and the twelve signs give twelve different answers: every house from the 1st to the 12th occurs exactly once. The 1st belongs to Aries, the 8th to Taurus, the 3rd to Gemini, and so on as the table shows. Among the sixteen charts only the D20 and the D40 spread their first parts over all twelve houses like this. The navamsa, by comparison, only ever starts on the 1st, 5th and 9th, and the D16 only on the 1st, 4th, 7th and 10th.

Own-Sign Arcs: Twenty, Spread Over the Twelve Signs

The house on which a sign’s count starts decides how often it meets its own name. Twenty parts run through the first eight signs of the count twice and the last four once. A sign whose count starts on its 1st, or anywhere from its 6th to its 12th, reaches its own name within those first eight, and so meets it twice, twelve parts apart: Aries, Taurus, Cancer, Virgo, Libra, Sagittarius, Aquarius and Pisces. The four signs that start on their 2nd, 3rd, 4th and 5th meet it once: Gemini, Leo, Scorpio and Capricorn. That makes 20 own-sign arcs over the zodiac, the same number as there are parts in a sign.

Agreement between the birth-chart sign and a varga sign is what vargottama names; the vargottama guide does it for the navamsa, and the D20 arcs above are a separate set.

How Often Each Sign Appears

Inside one row, eight signs occur twice and four occur once; in every row the four single ones are the 9th to 12th signs counted from its first sign, so for a movable sign they are Sagittarius, Capricorn, Aquarius and Pisces. No sign is missing from any row. Across all twelve rows the uneven spread within a row evens out completely: every sign appears twenty times in the 240-cell table, one appearance per round of the chain.

D20 Chart Calculator, Done by Hand

Suppose a graha stands at 8°45′ Aquarius. Aquarius is fixed, so its row is the fixed column. Divide 8.75 by 1.5 to get 5.83; the whole number, 5, plus one gives part 6 (7°30′–9°00′), and the fixed column reads Taurus there. The chain gives a check that needs no table: the graha is 308.75° from 0° Aries, which is 205 complete parts of 1°30′; 17 rounds of twelve leave 1, and 1 sign on from Aries is Taurus. Repeat for the lagna and each graha and set them out with the lagna’s D20 sign as the first house. The D9 navamsa guide follows the same steps for the ninth division. The degrees come from the Kundli report, which prints every graha’s; the free kundli prints the lagna’s only.

Limits of This Page

The page does not say what a D20 placement means. It names no deity, mantra, practice or spiritual path for any sign or graha, gives no strength or score to any cell, and gives no timing. The construction is the Parashari one as the site’s varga code encodes it; other schemes are not covered, and the use line is quoted as that list’s, not adopted as a finding.