D9 chart calculator (navamsa chart online)

This navamsa calculator draws the D9 chart from the date, time and place of birth: the navamsa sign of the Lagna and of every planet, which planets are vargottama, and both charts side by side in the North or South Indian style. Without a birth time it lists each planet’s navamsa through the day.

What the navamsa (D9) chart is

The Brihat Parashara Hora Shastra describes sixteen divisional charts (the shodashavarga), each made by cutting every sign into equal parts. The navamsa, “ninth part”, cuts each sign of 30° into nine parts of 3°20′. Each part is given a sign, and every planet and the Lagna are placed in the sign of the part they fall in. Of all the divisional charts the navamsa is the one most often read next to the birth chart: traditions consult it for marriage and partnership, and to judge how strong a planet is.

How the navamsa is worked out

The nine navamsas of a sign run in zodiac order, starting from a sign that depends on the sign’s quality: movable signs start from the sign itself, fixed signs from the 9th sign and dual signs from the 5th sign. Counted this way the navamsas follow on without a break from one sign to the next, so the same result comes from one formula: divide the sidereal longitude by 3°20′ and count that many signs from Mesh. A planet at 17° of Vrishabh, for example, is in the 6th navamsa of Vrishabh; Vrishabh is fixed, so the count starts from Makar, and the 6th sign from Makar is Mithun.

In bold: the navamsa of the same sign, where a planet is vargottama (the 1st navamsa of a movable sign, the 5th of a fixed sign, the 9th of a dual sign).

Navamsa of each nakshatra pada

A nakshatra pada is also 3°20′, so each of the 108 padas is exactly one navamsa: Ashwini pada 1 is the Mesh navamsa, Ashwini pada 2 Vrishabh, and so on, nine times round the zodiac. If you know a planet’s nakshatra and pada, this table gives its navamsa sign.

Vargottama

A planet in the same sign in the birth chart and the navamsa is called vargottama, “best in its division”. Classical texts count it as a source of strength for that planet. It happens in one navamsa of every sign, the bold cells of the table above, so in any chart a planet has about a one-in-nine chance of being vargottama. The Lagna can be vargottama too.

North Indian and South Indian charts

The calculator draws the D9 chart, and the birth chart next to it, in either style. In the North Indian (diamond) chart the houses stay in place: the top centre diamond is always the first house, the Lagna, and the houses run anticlockwise; the number in each house is its sign, 1 for Mesh to 12 for Meen. In the South Indian chart the signs stay in place: Mesh is second from the left on the top row and the signs run clockwise, and the Lagna is marked in its sign. Both show the same positions.

Worked example

For a birth in Delhi at 14:58 IST on 26 January 1950, the Lagna was at 4°59′ in Mithun, the 2nd of its nine navamsas, so the navamsa Lagna is Vrishchik. No planet is vargottama.

As Lagna (ascendant), Su Sun, Mo Moon, Ma Mars, Me Mercury, Ju Jupiter, Ve Venus, Sa Saturn, Ra Rahu, Ke Ketu.

How the calculator works

1. Convert the birth time to Universal Time with the UTC offset chosen.
2. Compute the sidereal (Lahiri) positions of the Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn, Rahu and Ketu in your browser, from a published planetary theory checked against NASA/JPL Horizons to within a few thousandths of a degree. The Moon is the same as on the site’s rashi and nakshatra calculators.
3. With a place, compute the Lagna from the sidereal time there (the same method as the Lagna calculator), and the clock window during which its navamsa stays the same. The Lagna is not worked out for places beyond 66° north or south.
4. Divide each longitude by 3°20′ to find its navamsa, and mark the bodies in the same sign in both charts.
5. Flag the D9 Lagna changing within five minutes of the time entered, the Moon within about 30 minutes of a navamsa edge, and the other planets within 0.05° of one. Without a time, work through the whole day.

Related tools

• Ashtakavarga calculator: the bhinnashtakavarga of each planet and the sarvashtakavarga of every sign.
• Lagna calculator: the rising sign (ascendant) of the birth chart, and when it changes.
• Atmakaraka calculator: the chara karakas, from the planets’ degrees in their signs.
• D10 chart calculator: the dasamsa, the divisional chart of ten parts per sign.
• D7 chart calculator: the saptamsa, seven parts per sign.
• D60 chart calculator: the shashtiamsa, sixty half-degree parts per sign.
• Rashi calculator by date of birth: the Moon sign, nakshatra and pada.
• Nakshatra calculator by date of birth: the Moon’s birth star used for naming.
• Dasha calculator: the Vimshottari periods from the birth nakshatra.
• Mangal dosha calculator: the house of Mars counted from the Lagna, the Moon and Venus.
• Kaal sarp dosh calculator: whether all seven planets lie on one side of Rahu and Ketu.