How the 36 gunas are worked out

The short version for parents

A match rests on four things: the date, time and place of birth, and the Moon's sign and nakshatra that come from them. Everything else is arithmetic on those.

Below, each koota has its rule written out one by one. Where books or calculators disagree, we say plainly which way we go.

Planet positions and the Lahiri ayanamsa

For planet positions we use astronomy-engine, an open-source astronomy library. It gives positions in the western (tropical) zodiac. We subtract the Lahiri (Chitrapaksha) ayanamsa to get positions in the Indian (sidereal) zodiac, the standard behind India's national calendar. We use the true ayanamsa, which includes the small wobble of the Earth's axis (nutation).

The lagna comes from the local sidereal time, the latitude and longitude of the birth place and the tilt of the Earth's axis. Rahu is the mean lunar node and Ketu sits exactly opposite. Houses are whole-sign houses counted from the lagna.

From the Moon to the nakshatra

The zodiac is divided into 12 signs of 30 degrees and 27 nakshatras of 13 degrees 20 minutes, and each nakshatra has four charans. Abhijit is not counted. All eight kootas are set by the Moon's sign, nakshatra and charan at birth. The kootas and their points are in the table below.

Varna (1 point)

The varna of a Moon sign comes from its element: water signs (Karka, Vrishchika, Meena) are Brahmin, fire signs (Mesha, Simha, Dhanu) Kshatriya, earth signs (Vrishabha, Kanya, Makara) Vaishya and air signs (Mithuna, Tula, Kumbha) Shudra.

If the boy's varna equals or ranks above the girl's (order: Brahmin, Kshatriya, Vaishya, Shudra) he scores 1, otherwise 0. Calculators do not agree on Varna; this is the convention we follow.

Vashya (2 points)

Each Moon sign belongs to one of five groups. Mesha and Vrishabha are chatushpada; Mithuna, Kanya, Tula and Kumbha are manava; Karka and Meena are jalachara; Simha is vanachara; Vrishchika is keeta. The first 15 degrees of Dhanu are manava and the rest chatushpada. The first 15 degrees of Makara are chatushpada and the rest jalachara (Muhurta Chintamani 6.23).

The points come from the table below. Only the manava and keeta cells change with the direction, boy to girl or girl to boy.

Tara (3 points)

Count from one nakshatra to the other, both ends included, divide by 9 and keep the remainder; a remainder of 0 counts as 9. The nine taras are Janma, Sampat, Vipat, Kshema, Pratyari, Sadhaka, Vadha, Mitra and Param Mitra. Vipat (3), Pratyari (5) and Vadha (7) are taken as unfavourable.

Tara is counted both ways: the girl's star from the boy's, and the boy's from the girl's. Each favourable direction gives 1.5, so Tara scores 0, 1.5 or 3. Calculators differ here too; this is the way we count.

Yoni (4 points)

Every nakshatra has an animal symbol, 14 animals in all. The points come from the standard 14 by 14 yoni table, as given in the open-source PyJHora library. The same animal scores 4. Seven pairs of natural enemies (mahavaira) score 0: horse and buffalo, elephant and lion, sheep and monkey, serpent and mongoose, dog and deer, cat and rat, cow and tiger.

Graha Maitri (5 points)

The lords of the two Moon signs are compared by Parashara's natural friendships (Brihat Parashara Hora Shastra, chapter 3). The lords: Mars for Mesha and Vrishchika, Venus for Vrishabha and Tula, Mercury for Mithuna and Kanya, the Moon for Karka, the Sun for Simha, Jupiter for Dhanu and Meena, Saturn for Makara and Kumbha.

Each lord sees the other as friend, neutral or enemy, and the two views are combined. The same lord, or two lords who are friends of each other, gets the full 5 points.

Gana (6 points)

Each nakshatra belongs to the deva, manushya or rakshasa gana. The direction is taken from the verse in Jyotirnibandha: a rakshasa boy with a deva girl scores 1, while a deva boy with a rakshasa girl scores 0. Some sites print the same table the other way round.

Bhakoot (7 points)

Count the signs from one Moon sign to the other. The pairs 2 and 12, 5 and 9, and 6 and 8 score 0, and that is Bhakoot dosha. Every other pair, including 1 and 1, 3 and 11, 4 and 10 and 7 and 7, gets the full 7.

Nadi (8 points)

Each nakshatra has an Adi, Madhya or Antya nadi. The same nadi scores 0, and that is Nadi dosha. Different nadis score the full 8.

The total, the minimum and the bands

The eight kootas add up to 36. This site uses one minimum everywhere: 18 points. A total of 24 and above is read as good, 18 to 23 is acceptable, and below 18 is under the minimum.

The dosha lines weigh more than the total. A parihar never changes the points; it shows on the dosha line instead.

Doshas and the parihar rules that cancel them

A dosha is shown when Nadi scores 0, when Bhakoot scores 0, or when Gana scores 1 or less. On the result every parihar rule is printed with its name and the fact that made it apply. We use only classical rules that are widely accepted.

• Nadi: same Moon sign, different nakshatra (Muhurta Chintamani 6.33, Jyotirnibandha).
• Nadi: same nakshatra, different Moon sign (same verse).
• Nadi: same nakshatra and sign, different charan (Piyushadhara commentary).
• Bhakoot: both Moon signs have the same lord (Muhurta Chintamani 6.30 to 6.31).
• Bhakoot: the Moon-sign lords are friends of each other (same verse).
• Gana: the Moon-sign lords are the same planet or friends of each other (Piyushadhara).

Manglik

A person is Manglik when Mars sits in house 1, 4, 7, 8 or 12 counted from the lagna. We look from the lagna only, not from the Moon or Venus as some texts also do. This needs the exact time of birth.

Two parihars apply to one person: Mars in its own sign (Mesha, Vrishchika) or its exaltation sign (Makara); and Jupiter in the same sign as Mars, or Mars in the 5th, 7th or 9th sign from Jupiter. For a couple: when both are Manglik and neither has a parihar, the two doshas cancel each other.

When the birth time is unknown

The main result uses the Moon at 12:00 noon Indian time. We then find every position the Moon takes from 00:00 to 23:59 on the birth date, with the time window each covers, and match for each position.

A koota that scores the same in every position shows as certain. Otherwise it says could change and shows its range, and the total comes as a range too. Doshas are shown the same way. Manglik needs the birth time.

Matching by name

The first sound of a name is looked up in the standard 108-syllable Avakahada chakra, which gives a nakshatra and charan. The Moon is placed at the middle of that charan and the eight kootas are scored. The result is marked approximate and Manglik is not checked.

Birth places and the clock

For now birth places are limited to India, from a list of more than 1,100 populated places taken from GeoNames. Older names such as Bombay, Madras and Calcutta lead to today's city.

Every birth time is converted with a fixed Indian Standard Time of UTC+5:30. Before 1 September 1947 parts of India kept other clocks, for example Bombay time, about 4 hours 51 minutes ahead of UTC, and clocks ran an hour ahead from 1 September 1942 to 15 October 1945. We do not correct for either, so for births in those years the Moon may fall in a neighbouring charan.