How an Akṣavedāṃśa D45 Chart Is Calculated

The D45 rule in the text

Bṛhat Parāśara Horā Śāstra 6.4 lists Akṣavedāṃśa among its sixteen vargas. Verse 6.31 says that the reckoning begins with Aries for a movable rāśi, Leo for a fixed rāśi, and Sagittarius for a dual rāśi. The movable group is Aries, Cancer, Libra, Capricorn; the fixed group Taurus, Leo, Scorpio, Aquarius; the dual group Gemini, Virgo, Sagittarius, Pisces. Every new D1 sign restarts the 45-part count at its modality’s seed, rather than continuing from the previous D1 sign.

Normalize a sidereal longitude to 0°–360°. Take its D1 sign as the integer part of longitude ÷ 30° and its degree within the sign as the remainder. The zero-based portion index is the integer part of that remainder ÷ (2/3°). Add one for the human-readable portion number. Add the zero-based portion index to the modality’s seed sign and wrap by twelve. An exact 40′ line belongs to the portion beginning there; 30° begins the next D1 sign.

All 45 Akṣavedāṃśa portions

Each cell combines the assigned D45 sign and its traditional presiding deity. The three modality columns apply to every D1 sign in that group. Verse 6.32 says the deity order repeats fifteen times across the 45 portions. On a narrow screen, scroll the table horizontally to compare the columns.

Work the boundary examples

At 20°30′ Aries, 20.5 ÷ (2/3) = 30.75, so the 31st portion applies. Aries is movable: count 30 signs forward from Aries and the D45 sign is Libra, with Brahma as the first deity in the next triad. At 14°20′ Taurus, 14⅓ ÷ (2/3) = 21.5, so the 22nd portion applies. Taurus is fixed: count 21 signs forward from Leo and the D45 sign is Taurus, with Shiva.

At exactly 0°40′ Taurus, the second fixed portion begins and maps to Virgo with Vishnu. One arcsecond before that line remains in the first portion: Leo with Shiva. At exactly 30° Aries, the D1 sign becomes Taurus and its first D45 portion begins with Leo. The 45th portion of a dual sign, from 29°20′ up to but excluding 30°, maps to Leo with Shiva.

Deities and interpretation

In movable rāśis the three-part deity cycle is Brahma, Shiva, Vishnu. In fixed rāśis it is Shiva, Vishnu, Brahma. In dual rāśis it is Vishnu, Brahma, Shiva. This ordering follows 6.31 and 6.32, and is also set out in a modern traditional explanation. The deity is a label on a portion; it is distinct from the D45 sign and is not an additional planet.

Parāśara 7.6 says to examine “everything” through D45 and D60. Some modern astrologers focus D45 specifically on paternal inheritance. That narrower theme is a later interpretive convention, not the wording of the cited verse. Treat any chart interpretation as a cultural practice rather than a measured outcome.

Inputs and precision

The underlying D1 comes from Astronomy Engine 2.1.19 and this site’s approximate Lahiri ayanamsha. It is not Swiss Ephemeris. The D45 Lagna requires a recorded birth instant, birthplace coordinates, and the correct historical UTC offset. The form accepts dates from 1800 through 2100 but does not look up historical time-zone changes. The site’s D1 uses mean lunar nodes. Another ayanamsha, ephemeris, node convention, or birth-time correction can alter placements near a 40′ edge; the result warns within 0.05° of one.

No within-sign D45 longitude is fabricated. The result keeps the underlying sidereal D1 position visible and reports only the traditional sign and deity assignments. If your birth time is unknown, no dependable D45 ascendant can be produced here.