Parivartana Yoga: two planets in each other's signs, how the engine grades it, and a worked chart

Parivartana means exchange. When two planets each stand in a sign the other rules, the texts treat them as trading places - each lord is "at home" in the other's house - and the two houses they rule become linked. It is one of the oldest and most widely used relationships between house lords, and the engine reports it as Parivarthana Yoga. This page states the rule and the engine's grading exactly, sets out the classifications in the library's texts - which are finer than the engine's - and walks through a chart. For what any yoga is worth in general, see what a yoga in your chart means; the term itself has a glossary entry.

The rule: how Parivartana Yoga forms

1. 1.Take any two of the seven planets Sun to Saturn. Rahu and Ketu rule no sign in this engine and are never part of an exchange.
2. 2.Planet A must be in one of planet B's own signs, and planet B in one of planet A's own signs. Mars in Aquarius with Saturn in Scorpio qualifies; so does Mars in Capricorn with Saturn in Aries, since each planet has two signs.
3. 3.Each exchanging pair is reported as its own entry, so a chart can show two Parivartana Yogas at once.

Signs are what matter, not degrees. The Sun and Moon rule one sign each, so the only Sun-Moon exchange is the Sun in Cancer with the Moon in Leo; Mercury and Venus each rule two, so their pair has four possible exchanges.

How the engine grades an exchange

The engine then looks at which houses, counted as whole signs from the ascendant, each planet rules. If both planets rule at least one kendra or trikona (1st, 4th, 5th, 7th, 9th or 10th), it shows the favourable sentence: "Both planets rule angular or trine houses, so this exchange is classically read as strongly favourable." Otherwise it shows the mixed sentence: "At least one of these planets also rules a difficult house (6th/8th/12th), so this exchange's effect is mixed rather than purely positive."

What the classical texts say

Jyotisha Siddhanta Sara (Rama R. Rao, 1994; an image-only scan, read from its page images) makes Parivarthana one of its five categories of yoga (p. 145) and treats it on pp. 153-154. It counts the possible exchanges between the twelve house lords as 66 and divides them into three classes. Twenty-eight are "Maha yogas", described as auspicious and fortunate throughout life. Thirty are "Dainya yogas", caused by exchanges involving the lords of the 6th, 8th and 12th, described as bringing difficulties. Eight are "Kahala yogas", involving the 3rd lord, where the book quotes Manthreswara's reading of a mixed temper and mixed fortunes. It then notes a difference of opinion: some hold that an exchange among the lords of the 6th, 8th and 12th, if those lords aspect each other and are untouched by other lords, should instead be called a Vipareetha Raja Yoga.

BPHS uses exchange as a building block rather than as a named yoga. Ch. 34 Sl. 11-12 puts "an exchange between a Lord of a Kendr and a Lord of a Kon" first among the four relations that make a yoga, and Sl. 15 says that lords who also own an evil house do not cause Raj Yoga "by mere relations". Ch. 39 Sl. 6-7 names a Maha Raj Yog when the Lagna lord and the 5th lord exchange signs. The engine's favourable grade is close to Ch. 34's kendra-kona idea, but it does not apply Sl. 15, and the engine cites a further source (Kannan) that is not in the searchable library.

The two schemes disagree often, because they look at different things. The engine asks what else each planet rules; the JSS classes look at the two houses actually swapped. An exchange between, say, the 1st and the 8th is a Dainya yoga in JSS's terms, but it can still be graded favourable by the engine if the 8th-house planet also rules a kendra or trikona.

How rare it is

In the engine's sample at least one exchange was present in 1,111 of 3,000 sampled birth moments 1985-2060 - 37 percent. In 1,044 moments there was one exchange and in 67 there were two, 1,178 exchanges in all. With seven planets and twenty-one possible pairs, many with several sign combinations, an exchange somewhere in the chart is common. The most frequent pairs were Mercury and Venus (113), Jupiter and Venus (111) and Jupiter and Saturn (100); the rarest was the Moon and Jupiter (16), because the Moon passes through a sign in a few days.

Two patterns stand out. Pairs that include the Sun or the Moon are rarer, because each rules only one sign, so there is only one way for them to exchange with a given partner (two ways when the partner rules two signs, against up to four for two two-sign planets). And pairs of slow planets such as Jupiter and Saturn can stay exchanged for months, so a sample of moments meets them often once the arrangement occurs. A Sun-Mercury exchange needs the Sun in Gemini or Virgo and Mercury in Leo - always in neighbouring signs, since Mercury never strays far from the Sun.

Worked example: the first moment of the walk

The engine's search starts at 1 January 1985, 06:00 IST, New Delhi, and that moment has an exchange. Re-enter it in the birth chart calculator. The ascendant is Scorpio at 28.81 degrees.

1. 1.Mars is in Aquarius, which Saturn rules. Saturn is in Scorpio, which Mars rules. That is an exchange.
2. 2.Mars rules the 1st (both a kendra and a trikona) and the 6th. Saturn rules the 3rd and the 4th (a kendra). Both rule at least one kendra or trikona, so the engine grades it favourable.
3. 3.The houses actually exchanged are the 1st (Scorpio, where Saturn sits) and the 4th (Aquarius, where Mars sits).

The engine reports Parivarthana Yoga with Mars and Saturn, the sentence "Mars and Saturn sit in each other's sign - a mutual exchange", and the favourable reading. Now apply the texts. In JSS's terms the exchanged houses are the 1st and 4th, neither a dusthana nor the 3rd, so this is one of the Maha yogas. In BPHS Ch. 34 terms it is an exchange between a kendra-and-kona lord (Mars, lord of the 1st) and a kendra lord (Saturn, lord of the 4th) - but both also rule other houses, Mars the 6th and Saturn the 3rd, which is what Sl. 15 warns about. The engine's sentence and the JSS class agree here; a strict reading of Sl. 15 would hesitate. The same chart also returns Vasi, Kedara and the Kendra-Kona Raj Yoga.

Parivartana beside its neighbouring yogas

The engine's lordship yogas divide BPHS's relations between them. The Kendra-Kona Raj Yoga covers conjunction and mutual aspect between kendra and kona lords; Dharma-Karmadhipati and the Raja Yoga of the 5th and 9th lords cover conjunctions of particular pairs; and Parivartana covers exchange, for any pair. A 9th-10th exchange, for example, is reported here and not as Dharma-Karmadhipati. The exchanges JSS calls Dainya overlap in idea with the Vipareeta Raja Yogas (Harsha, Sarala, Vimala), which the engine tests by placement rather than exchange.

What the rule does and does not establish

Parivartana establishes that two planets occupy each other's signs, linking the houses they rule. The texts read exchanges differently by class - auspicious, troubled or mixed in JSS, a building block of Raj Yoga in BPHS - and the engine adds its own two-way grade, with the sentence caveat noted above. None of these sources gives exchange a timing rule of its own. A yoga is a named rule about positions, not a promise, and with more than a third of sampled charts showing one, its presence alone says little; which houses are exchanged, and what else the two planets rule, says considerably more. Those are the details to read in your own result.

To see whether your chart has an exchange, between which planets, and how the engine grades it, run the yoga calculator.

Questions about Parivartana Yoga

What is Parivartana Yoga?

Two planets each in a sign the other rules - a mutual exchange of signs, linking the houses they rule.

Are Parivartana and Parivarthana the same?

Yes. The engine and Jyotisha Siddhanta Sara spell it Parivarthana; this page uses the common spelling Parivartana.

Can Rahu or Ketu take part in an exchange?

Not in this app. The nodes rule no sign in the engine, so only the seven planets Sun to Saturn are checked.

Why does the app call my exchange mixed when neither planet rules the 6th, 8th or 12th?

Because the code grades an exchange mixed whenever the two planets do not both rule a kendra or trikona, while its sentence gives a dusthana as the reason. In the sample that mismatch affected 118 of 591 mixed exchanges. It has been reported.

How common is it?

At least one exchange appeared in 1,111 of 3,000 sampled birth moments 1985-2060; 67 of those moments had two.

What are Maha, Dainya and Kahala yogas?

Jyotisha Siddhanta Sara's three classes of exchange (pp. 153-154): Maha (auspicious), Dainya (involving the 6th, 8th or 12th lord) and Kahala (involving the 3rd lord). The engine does not compute them.

Which exchange is most common?

In the engine's sample, Mercury and Venus (113 of 1,178 exchanges), then Jupiter and Venus (111) and Jupiter and Saturn (100). The Moon and Jupiter was rarest, at 16.

Is an exchange between the 9th and 10th lords Dharma-Karmadhipati Yoga?

Not in this app. Dharma-Karmadhipati requires the two lords in the same house. An exchange between them is reported here, as Parivarthana Yoga, and BPHS Ch. 34 counts it as a kendra-kona relation.

Should I do anything about an exchange in my chart?

No. It is a named rule about positions. This app does not prescribe remedies.