How a Bhāṁśa D27 Chart Is Calculated

Where the four starts come from

Bṛhat Parāśara Horā Śāstra 6.26 names Aries and the other movable signs for the Bhāṁśa distribution. In zodiac order the four movable signs are Aries, Cancer, Libra, and Capricorn. The modern element-group presentation assigns these starts to fire, earth, air, and water respectively: Aries, Leo, Sagittarius start at Aries; Taurus, Virgo, Capricorn at Cancer; Gemini, Libra, Aquarius at Libra; Cancer, Scorpio, Pisces at Capricorn. The rule then counts forward through signs for each of the 27 portions. The D27 table published by PJC independently lists the same four sequences.

Verses 6.24–25 enumerate nakṣatra presiding deities, and verse 26 discusses their order for odd and even signs. This calculator applies the four sign starts, not a separate deity lookup. Bhāṁśa, Saptaviṁśāṁśa, and Nakṣatrāṁśa are often used as labels for D27; some teaching traditions distinguish a different Nakṣatrāṁśa mapping. This page names its selected Parāśari Bhāṁśa sign rule so the result can be compared responsibly.

All twenty-seven exact intervals

Each interval includes its start and excludes its end. At exactly 1°06′40″ within a D1 sign, portion two begins. At exactly 30°, the next D1 sign begins with a new starting sign. The chart repeats the sign sequence after twelve portions, but the derived degree still depends on the position within the current narrow interval.

Calculate a D27 placement by hand

Normalize the sidereal D1 longitude to 0° through just under 360°. Let s be its zero-based D1 sign index (Aries = 0), and d its degree within that sign. The portion width w is 30° ÷ 27 = 1°06′40″. The zero-based portion p is floor(d ÷ w), from 0 to 26. The starting sign index is (3s) modulo 12, which cycles Aries, Cancer, Libra, Capricorn as s advances. The D27 sign index is (3s + p) modulo 12. The D27 degree is 27 × (d − p w).

At 10° Taurus, s = 1 and p = 9, so the tenth portion starts at 10°. Counting nine signs after Cancer lands in Aries, at 0° D27 Aries. At 10°30′ Taurus the same portion displays 13°30′ Aries. At exactly 1°06′40″ Aries, the second portion begins in Taurus; one arcsecond earlier remains in the first portion in Aries. At exactly 30° Aries, the D1 sign becomes Taurus, whose first D27 portion begins at Cancer.

Interpretive scope and data limits

Parāśara 7.5 links Bhāṁśa with relative strength and weakness. That is a statement of traditional use, not scientific evidence that this remapping assesses constitution, mental state, or future outcomes. Read it beside D1 and identify the chosen convention when comparing charts.

A recorded time, place, and historical UTC offset are needed for D27 Lagna. A position within 0.05° of a 1°06′40″ boundary receives a local caution. Birth-time uncertainty, ayanamsha choice, ephemeris, and lunar-node convention can change close placements. The base D1 calculation uses Astronomy Engine 2.1.19 and an approximate Lahiri ayanamsha, not Swiss Ephemeris. The local-date form covers 1800–2100 and does not reconstruct past time zones.