The Navamsa (D9) chart: the calculation

Definition

The Navamsa (D9) is a divisional chart: each 30° sign is divided into nine parts of 3°20', and each part is assigned a sign.

Formula

part = floor((longitude within sign) ÷ 3°20'), from 0 to 8. Starting sign: movable signs (Aries, Cancer, Libra, Capricorn) start from themselves; fixed signs (Taurus, Leo, Scorpio, Aquarius) from the 9th sign from them; dual signs (Gemini, Virgo, Sagittarius, Pisces) from the 5th. Navamsa sign = (starting sign + part) mod 12.

Worked example

A planet at 19° Libra. Libra is movable, so the sequence starts at Libra. 19 ÷ 3.333 = 5.7, so part 5. Libra + 5 = Pisces: the planet is in Pisces in the Navamsa.

Padas and vargottama

A nakshatra pada is also 3°20', so each pada falls in exactly one Navamsa sign; the four padas of a nakshatra are four consecutive Navamsa signs. A planet in the same sign in D1 and D9 is called vargottama.

In Jyotishya

Your Navamsa is drawn beside your birth chart in North or South Indian style. The calculation matches the Swiss Ephemeris reference implementation for every planet and the ascendant.