Rahu in Vedic astrology: what the classical texts say about the north node, and where they stop

Seven of the nine grahas are things you can point at in the sky. Rahu is not. It is the place where the Moon's path crosses the Sun's path going north: a calculated point with no light, no disc and no mass. Ketu is the same crossing on the opposite side of the zodiac. Yet Rahu holds the third-longest period in the Vimshottari Dasha, eighteen years, and a line of its own in every birth chart.

This page collects what the classical texts in this app's library say about Rahu - Brihat Parashara Hora Shastra (BPHS), Kalyana Varma's Saravali and Bhrigu Sutras, with S.S. Chatterjee's Advanced Predictive Astrology for modern practice - and sets it beside what this app's engine computes. Rahu differs from siblings such as Saturn or the Moon in two ways: the texts say less about it and disagree more, and this app therefore leaves it out of several calculations. Both are spelled out below, with chapter and sloka, so you can hold the rules against your own birth chart. Nothing here is a prediction about you. Ketu has its own page.

What Rahu is: a point on the Moon's orbit

Bhrigu Sutras (Part I, section 8, pp. 12-13) gives the geometry plainly. The Moon's orbit is tilted about 5 degrees to the Sun's apparent path, so the two cross at two points exactly 180 degrees apart. The crossing where the Moon passes from south to north is the ascending node, Rahu; the other is the descending node, Ketu. The book calls them shadowy planets: points without shape or mass, whose position can be calculated as exactly as the Sun's and never checked by eye. The translator's gloss at BPHS Ch. 3 Sl. 11 likewise calls them the ascending and descending nodes of Candr, the Moon.

The nodes move backwards through the zodiac. Bhrigu Sutras gives the rate as 19 degrees 20 minutes a year and about 18 months a sign; R. Santhanam's note at BPHS Ch. 3 Sl. 6 gives about 3 minutes of arc a day. This app's engine computes Rahu as the mean node, and its numbers agree: 19.34 degrees a year, 3.18 minutes of arc a day, a full circuit in about 18.6 years. On the engine's own sidereal positions Rahu spends 566 days in each sign, a little more than the round 18 months. Ketu is not computed separately: it is Rahu plus 180 degrees, to the last decimal.

Two consequences follow. Rahu is always retrograde - BPHS Ch. 47 Sl. 3-4 says so outright, and the engine sets the flag on every chart - so "Rahu (R)" on a printout tells you nothing about your chart in particular. And Rahu is never marked combust: the engine's combustion orbs cover the Moon and the five visible planets only.

The same section retells the Puranic story behind the names. An asura who stole a share of the nectar of immortality was pointed out by the Sun and the Moon and cut in two; the head became Rahu and the body Ketu, and their pursuit of the luminaries is the story's account of eclipses. The book then sets the story aside and treats the nodes as points with a regular, predictable motion.

What the texts attribute to Rahu

BPHS Ch. 3 describes the grahas attribute by attribute, and for most attributes its lists stop at Saturn. What it does give Rahu is brief. Sl. 11 counts Rahu and Ketu among the malefics, with the Sun, Saturn, Mars and the waning Moon. Sl. 14-15 make the Sun and Moon royalty, Mars the army chief, and Rahu and Ketu the army itself. Sl. 30 is the only description: a smoky look, a bluish body, a dweller in forests, fearsome, windy in temperament and intelligent - and Ketu, it adds, "is akin to Rahu".

Saravali is thinner still. Ch. 4 Sl. 1-2 maps the grahas onto the cosmic person: the Sun is the soul, the Moon the mind, and Rahu the ego. Sl. 8 gives Rahu the south-west. After that the name appears only in the chapters on afflictions at birth and their cancellation (Ch. 10 and 12): nine mentions in the whole translation. Its sign-by-sign chapters (Ch. 22-29) and its chapter on houses (Ch. 30) run from the Sun to Saturn, so there is no "Rahu in Aries" in Saravali to quote. Bhrigu Sutras notes the gap itself.

Dignity: three schemes in the texts, none in this app

For the seven visible grahas, exaltation and debilitation are settled in one passage, BPHS Ch. 3 Sl. 49-54, and that passage stops at Saturn. Rahu's dignities turn up forty-four chapters later, as a preamble to its Dasha. BPHS Ch. 47 Sl. 34-39 says Rahu is exalted in Vrishabh (Taurus), has its Moolatrikona in Mithun (Gemini) and owns Kumbh (Aquarius), and then records that some sages make Kanya (Virgo) its own sign instead. Ketu gets the mirror image, exalted in Vrischik (Scorpio), which by the seventh-sign rule of Ch. 3 is where Rahu is debilitated.

Bhrigu Sutras (Part I, pp. 12-13) calls the question a controversy among the ancients and sets out two positions. Uttara Kalamrita, it reports, agrees with BPHS. Sanketnidhi instead exalts Rahu in Gemini and gives it Virgo as its own sign. The commentator's own view, stated on p. 4 and again after the house sutras (pp. 114-115), is a third: being shadow planets, the nodes own no sign at all, and act through the sign they occupy, its lord, and the grahas that join or aspect them.

Practice is no more uniform. In one case study Chatterjee (Advanced Predictive Astrology Vol. II, p. 65) reads a debilitated Rahu as rescued because its dispositor, Jupiter, is exalted. A Rahu whose sign lord is Jupiter is in Sagittarius or Pisces, not Scorpio, so he is not working from BPHS's scheme. And BPHS itself is not tidy: outside Ch. 47 it keeps naming signs in which Rahu behaves well, and the lists do not match.

• Ch. 55 Sl. 1-4, Rahu's own sub-period: Cancer, Scorpio, Virgo or Sagittarius.
• Ch. 57 Sl. 68, Rahu's sub-period in Saturn's Dasha: Aries, Virgo, Cancer, Taurus, Pisces or Sagittarius.
• Ch. 58 Sl. 47-49, in Mercury's Dasha: Aries, Aquarius, Virgo or Taurus.
• Ch. 45 Sl. 123-134, Rahu in the Sayana avastha: Taurus, Gemini, Virgo or Aries turn a poor state into a prosperous one.
• Ch. 50 Sl. 42, sign-based Dashas: the four signs counted from Aquarius - Aquarius, Pisces, Aries and Taurus - belong to Rahu.
• Saravali Ch. 12 Sl. 10-11 and Bhrigu Sutras Sutras 1-4: Rahu rising in Aries, Taurus or Cancer.

Taurus, Aries and Virgo recur most often. Scorpio, the debilitation sign implied by Ch. 47, is on the favourable list in Ch. 55. A reading that hangs a verdict on "Rahu exalted" or "Rahu debilitated" is choosing one line of one chapter over the others.

What this app does with all that

The engine's dignity table has seven entries, and Rahu is not one of them. Ask it for Rahu's dignity in any of the twelve signs and it returns the same label, Neutral; we ran all twelve. There is no exaltation or debilitation, no row in the friends-and-enemies table, and no score in the Vimshopaka Bala calculator, whose own note says a number for the nodes would have nothing behind it. This is a deliberate refusal to pick one of the disputed schemes, and it has three consequences on screen that are easy to misread.

• The planet-in-house reading on the Kundali page prints its favourable line only for a graha with a strong dignity outside the 6th, 8th and 12th houses. Rahu's dignity is never strong, so Rahu gets the testing line in every chart.
• The Mahadasha reading applies BPHS Ch. 47 Sl. 5-6: favourable in the ascendant, or in exaltation, its own or a friendly sign. With no dignity to test, a Rahu Mahadasha is labelled favourable only when Rahu is in the 1st house.
• There is no Rahu row in the Shad Bala calculator. That follows BPHS Ch. 27, which opens by saying the six-fold strength is worked out for the seven grahas and that the nodes are not considered.

So a testing line beside your Rahu is not a finding that your Rahu is afflicted. It is what the engine prints for a graha it has no dignity to grade.

Aspects: the 7th, which is always where Ketu sits

BPHS Ch. 26 Sl. 2-5 gives every graha a full aspect on the 7th house from itself and reserves the special full aspects for three grahas by name: Saturn on the 3rd and 10th, Jupiter on the 5th and 9th, Mars on the 4th and 8th. Rahu is not named anywhere in the chapter. If another program shows Rahu aspecting the 5th and 9th from itself, it is applying a convention this chapter does not state.

This app gives Rahu the 7th-house aspect and nothing else. Because Ketu is always exactly opposite, that aspect always lands on Ketu's house, and Ketu's lands on Rahu's. So any graha sharing a house with one node is also aspected by the other, and the engine counts both nodes as malefics. Three calculations feel it.

• Shad Bala's aspect component: a graha in either node's house scores 0 of 3 if only malefics aspect that house, and 1.5 if a benefic does too.
• Chandradhi (Adhi) Yoga and Amala Yoga in the yogas calculator: both need a benefic free of malefic conjunction and aspect, so a benefic on the Rahu-Ketu axis never qualifies.
• Kemadruma Yoga: it needs an unaspected Moon, and a node opposite the Moon counts as an aspect, so it cannot form with the Moon on the axis.

Rahu in the twelve houses

BPHS states the governing rule in one line, Ch. 34 Sl. 16: Rahu and Ketu mainly give the results of the house lord they are joined with, or of the house they occupy. Sl. 17 adds how a node becomes a Yoga Karaka: in a kendra, joined or aspected by the lord of a trikona or kendra. The Bhrigu Sutras commentary (pp. 114-115) ranks the influences: a node acts first for the graha it is conjoined with, failing that for the graha aspecting it, and only when alone for the lord of its sign. It cites Uttara Kalamrita that the nodes turn auspicious in a kendra or trikona, or with a kendra or trikona lord.

The 3rd, 6th and 11th: where the sources agree

On one point the sources converge to an unusual degree: Rahu does well in the 3rd, 6th and 11th houses.

• Saravali Ch. 12 Sl. 3-5: Rahu in the 3rd, 6th or 11th from the ascendant, aspected by benefics, cancels the afflictions the previous chapters describe.
• BPHS Ch. 48 Sl. 18-20 lists the 3rd, 6th and 11th as unfavourable for Dasha purposes, then carries a note excepting the nodes: Rahu and Ketu give favourable results there.
• BPHS Ch. 55 Sl. 1-4, Ch. 53 Sl. 15-16 and Ch. 60 Sl. 38-39: Rahu's sub-periods read well with Rahu in the 3rd, 6th, 10th or 11th.
• Bhrigu Sutras: in the 3rd, material abundance; in the 6th, a tolerant and very happy person; in the 11th, children and wealth.
• Chatterjee (Vol. II, p. 121): Rahu in the 3rd, 6th or 11th from the ascendant or the Moon brings material gains in its own periods, more so when a benefic aspects it.

The difficult houses are nearly as consistent. BPHS Ch. 47 Sl. 40 names the 8th and 12th for a troubled Dasha. Ch. 44 Sl. 22-24 names the 6th, 8th and 12th and adds the exception that matters: not if Rahu is joined or aspected by a benefic. The 2nd and 7th are flagged in almost every sub-period chapter; these are the classical Maraka houses, a longevity-timing label this app does not use.

House by house in Bhrigu Sutras

Bhrigu Sutras gives the nodes 32 sutras across the twelve houses (pp. 109-115), the same for Rahu and Ketu on the reasoning that the two are always opposite, then quotes Phaladeepika (PD) and Chamatkar Chintamani (CC) for each node. Much of it is of a kind this app does not repeat: lifespans in years, predictions about spouses and children, a line about the afterlife. The table carries what is left, beside the line this app prints.

Read the two columns against each other at the 3rd, 6th and 11th. The sutras are at their most favourable there, and the app still prints a testing line, because its favourable line needs a dignity the engine does not assign to Rahu. That is a limit of the app's rule, not a statement about your chart. At the 9th and 10th the problem is different: the quoted authorities disagree with each other. Chatterjee, too, writes that Rahu in the 10th usually goes with innovation and a new path (Vol. II, pp. 28-30).

Each house has its own page: 1st, 2nd, 3rd, 4th, 5th, 6th, 7th, 8th, 9th, 10th, 11th and 12th.

Rahu in company

Since a node speaks first for whatever it is joined with, the texts say more about Rahu's company than about Rahu alone. Chatterjee adds working rules from his case files: a graha in close company with a node gives poorer results in its own period, the closer the worse (Vol. II, p. 124); the Moon with Rahu shows as self-confidence joined to distrust of others, which Jupiter in a kendra or trikona from the pair turns into a careful, business-like attitude (p. 152); and Rahu linked with Mercury in the 3rd makes Rahu's Dasha impatient and changeable, a point he takes from Bhavartha Ratnakara (p. 159). These are one author's observations and this app tests none of them. The best-known Rahu combination of all, Kaal Sarp, is in none of the five astrology texts in this library; the Kaal Sarp article explains what the calculator computes and declines to claim, and found the pattern on about 7.4% of the days it sampled.

Seven-graha systems: where Rahu is left out

Several classical methods are built for the seven grahas from the Sun to Saturn. The table says what each source states about the nodes and what this app does, so a missing Rahu row is not mistaken for a bug.

The calculators concerned are Ashtakavarga, Char Karakas and Argala. One feature does give Rahu a role of its own. Career and Money counts Rahu in or opposite the 10th or 7th house as one sign of unconventional or self-made work, adds Rahu at a fixed weight to its risk-appetite reading when it sits in the 2nd, 5th, 8th, 11th or 12th, and says that a Rahu period is a thinner read than the others.

Timing, part one: the 18-year Mahadasha

BPHS Ch. 46 Sl. 12-15 sets out the Vimshottari order from Krittika - Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, Ketu, Venus - and the years: 6, 10, 7, 18, 16, 19, 17, 7 and 20. Rahu's 18 years are the third-longest share, 15% of the 120-year cycle. Counting every ninth nakshatra from the fourth lands Rahu on Ardra, Swati and Shatabhisha, and the engine returns exactly those three. A birth with the Moon in one of them starts life in Rahu's Mahadasha; everyone else meets it after Mars and before Jupiter. How the whole cycle works is in its own article, and the Rahu Mahadasha page goes through the period in detail.

Ch. 47 frames the reading with two general rules and then turns to Rahu itself.

• Sl. 3-4: a graha in the first third of its sign gives its Dasha results at the start, in the second third in the middle, in the last third at the end, and the order is reversed for a retrograde graha. Rahu and Ketu are always retrograde, so for them it is always reversed: a Rahu in the first ten degrees of its sign delivers at the end.
• Sl. 5-6: a Dasha lord in the ascendant, or in its exaltation, own or a friendly sign, is favourable; in the 6th, 8th or 12th, in debilitation or in an enemy's sign, unfavourable.
• Sl. 34-39: with Rahu in its exaltation sign and the like, the text lists gains of wealth, conveyances, a new house, children and recognition from a foreign government. With Rahu joined or aspected by benefics, in a benefic's sign, and in the 1st, 4th, 7th, 10th, 11th or 3rd house, it lists comforts through government favour, wealth through a foreign ruler and happiness at home.
• Sl. 40-43: with Rahu in the 8th or 12th, troubles of every kind; joined with a malefic or a Maraka, or debilitated, loss of position and strain at home. For this case the text gives the period a shape: losses at the start, some relief and gain in the middle, anxiety at the end.

One word keeps returning. Foreign governments and rulers appear in Ch. 47, journeys abroad in Ch. 55, prosperity in foreign places in Rahu's Prakash avastha (Ch. 45 Sl. 123-134). Chatterjee cites Jataka Chintamani for travel abroad with Rahu in the 1st, 7th or 12th (Vol. II, p. 88). This app's favourable Rahu theme - unconventional gains, ambition realised through foreign or unfamiliar channels - is drawn from that thread.

What this app prints for a Rahu Mahadasha

The app applies the Sl. 5-6 test, as it does for every Dasha lord. For Rahu the dignity half of that test can never pass, so the reading is favourable only with Rahu in the 1st house, and its separate three-way quality label can read neutral, or challenging with Rahu in the 6th, 8th or 12th, but never good. It does not test the conditions of Sl. 34-39, and it shows no house-lordship themes for the period, because Rahu owns no house in its lordship table. The testing wording speaks of instability, anxiety and outcomes that do not match the effort. Read it as the default for a graha the engine cannot grade, and check Sl. 34-43 yourself: they need only Rahu's sign, house and company. The Vimshottari Dasha calculator gives the dates, and the Timing feature shows the period in context.

The nine sub-periods

Each Antardasha takes its lord's share of the parent period. Rahu's Mahadasha is 18 years, or 216 months, so every sub-period lasts 1.8 months for each Vimshottari year its lord has. BPHS Ch. 55 takes them in the same order the engine does.

Ch. 55 judges most sub-lords a second time, by position counted from Rahu. A kendra or the 11th from Rahu is on every such list; the 6th, 8th and 12th from Rahu are the recurring difficult positions. It also flags a sub-lord that rules the 2nd or 7th house. For the difficult cases the chapter prescribes charities and recitations, which this app does not reproduce. The mechanics of sub-periods are in Antardasha and Pratyantardasha.

Rahu's own sub-period inside another graha's Mahadasha follows the same arithmetic the other way round: 1.8 months for each year of the parent period, from 10.8 months in the Sun's Dasha to 36 in Venus's. BPHS covers each in Ch. 52 to 60, and the conditions repeat. Rahu in its exaltation or own sign, in a kendra, a trikona or the 11th, or with benefics reads well; Rahu with malefics, or in the 8th or 12th from the Dasha lord, does not.

Modern authors add blanket rules. Chatterjee quotes R. Santhanam's list of sub-periods said to set careers back - Saturn-Rahu, Rahu-Saturn, Jupiter-Rahu, Rahu-Mercury, Mercury-Rahu and Rahu-Mars - and says he would add Rahu-Jupiter and Mars-Rahu, which Santhanam leaves out (Vol. II, p. 123). These are practitioners' observations from case files. Nothing in this app tests them, and BPHS Ch. 55's own conditions for the same sub-periods are more specific than any blanket list.

Rahu in the other Dasha systems

Vimshottari is not the only system that gives Rahu a period. BPHS Ch. 46 Sl. 17-20 describes Ashtottari, recommended when Rahu is in a kendra or trikona from the ascendant lord and not in the ascendant itself; there Rahu has 12 years and Ketu none. Sl. 27-28 (Dwadashottari) give Rahu 15 years, and Sl. 37-39 (Dwisaptati-sama) 9. The alternate Dashas calculator computes the last two among its six systems, and not Ashtottari. In the sign-based Chara Dasha, BPHS's worked example (Ch. 46 Sl. 167) gives Aquarius two lords, Saturn and Rahu. This app's Chara Dasha calculator follows it, counting Aquarius to Saturn or Rahu by the tests of Ch. 46 Sl. 158-166, and names the lord it used in its output.

Timing, part two: Rahu in transit

Rahu moves backwards through the signs: from Aquarius into Capricorn, not into Pisces. The table gives the engine's own dates for the mean node entering each sign. Ketu enters the opposite sign at the same minute.

The Gochar calculator reads all nine grahas from your natal Moon sign, following Kannan's chapter on transits as the engine records it. Rahu takes the malefic rules: favourable in the 2nd, 3rd, 6th and 11th from the Moon, testing in the 1st, 4th, 8th and 12th, and unremarked in the 5th, 7th, 9th and 10th, where the source gives malefics no rule. The 9th carries a separate flag, as the position that source singles out for Rahu. The calculator labels the stay as about 548 days, the source's round 18 months; the engine's own arithmetic makes it 566. Since the Moon sign is all this needs, the reading works from a birth date alone.

On the day this page was written, 5 October 2026, the engine has Rahu at 3.26 degrees of Aquarius in Dhanishta and Ketu at 3.26 degrees of Leo in Magha. For a Capricorn, Sagittarius, Virgo or Aries Moon that is Rahu in the 2nd, 3rd, 6th or 11th, the favourable set. For Aquarius, Scorpio, Cancer and Pisces Moons it is the 1st, 4th, 8th and 12th. From 6 December 2026 every one of those counts drops by one.

Rahu Kaal is not a transit

Rahu Kaal shares the name and nothing else. It does not depend on where Rahu is, or on your chart. It is one eighth of the time between sunrise and sunset, chosen by weekday: the 2nd eighth on Monday, the 3rd on Saturday, the 4th on Friday, the 5th on Wednesday, the 6th on Thursday, the 7th on Tuesday and the 8th on Sunday. This app's rules document takes that table from Drik Panchang, not from the classical texts in this library. BPHS Ch. 3 Sl. 66-69 does divide the day into eight parts, but to find Gulika: seven parts go to the weekday lords and the eighth has no lord. There is no part for Rahu. The Rahu Kaal calculator gives the window for your place and date, Choghadiya cuts the same daylight into the same eighths, and the muhurat scorer takes 25 points off any window that overlaps it.

A worked example: one Rahu, three readings

The planet pages in this series share one test chart: a birth on 3 November 2001 at 19:50 IST in Mumbai. The engine puts Rahu at 5.58 degrees of Gemini in Mrigashira pada 4, in the 2nd house from a Taurus ascendant, and Ketu at 5.58 degrees of Sagittarius in the 8th. The true node was 1.48 degrees further back, still in Gemini.

• By sign: under BPHS Ch. 47 this Rahu is in its Moolatrikona. Under Sanketnidhi it is exalted. Under this app it is Neutral, like every Rahu.
• By house: it is in the 2nd, one of the two houses the sub-period chapters flag, and outside the six houses Ch. 47 Sl. 34-39 names as supportive. The app prints its 2nd-house testing line and, since Rahu is not in the 1st, a testing Mahadasha reading.
• By timing: the Rahu Mahadasha runs from 7 October 2014 to 7 October 2032, and the sub-period at the time of writing is Venus, 26 April 2026 to 26 April 2029, the longest of the nine. Ch. 55 Sl. 46-59 judge it by Venus, and here the conditions point both ways. Venus is in the 5th house, a trikona, and in the 4th sign from Rahu, a kendra from the Dasha lord. It is also in Virgo, its debilitation sign, which the same passage puts on the difficult side.
• By drekkana: Rahu is in the first ten degrees of Gemini, so Ch. 47 Sl. 3-4 would have this Dasha deliver towards its end.

None of these lenses cancels the others, and the app does not net them into one verdict. Much of a Rahu reading is a choice of authority, and little of it survives being stated as a single adjective.

Rahu and the number 4

Rahu has a second life in this app, in numerology. The Vedic numerology books in its library assign the number 4 to Rahu and 7 to Ketu; one of them, the Academy of Vedic Vidya's course notes, adds that Western numerology gives 4 to Uranus and that the two should not be confused. In the numerology Dasha this app computes from those books, Rahu's period lasts 4 years of a 45-year cycle: a different clock from the 18 years of Vimshottari. The number 4 has its own page.

How to check your own Rahu in this app

1. 1.Open the birth chart with your date, time and place. The Rahu row gives its sign, degree, nakshatra and pada, and its house if the place resolved. Ketu is the same degree of the opposite sign. Rahu's sign needs only the date; its house is counted from the Lagna, so it needs the time and place.
2. 2.Note the house first. The 3rd, 6th, 10th and 11th are where the texts are kindest, the 8th and 12th where they are hardest, and the 2nd and 7th are the ones flagged for Rahu's periods.
3. 3.Note the company: which grahas share Rahu's house, which aspect it, and which graha rules its sign. By BPHS Ch. 34 Sl. 16 and the Bhrigu Sutras commentary, Rahu mostly speaks for them.
4. 4.Read the sign against the dignity table on this page, and treat the answer as disputed.
5. 5.Run the Kaal Sarp calculator to see whether all seven grahas sit on one side of the Rahu-Ketu axis, and whether the verdict would change on the true node.
6. 6.Run the Vimshottari Dasha calculator for the dates of your Rahu Mahadasha and its nine sub-periods, and the Gochar calculator for the house Rahu is transiting from your Moon.
7. 7.For finer work, the Navamsa calculator shows Rahu's sign in the D9, and the nakshatra sub-lord calculator lists Rahu's star lord and sub-lord.
8. 8.For everything side by side, use the Kundali feature, the accuracy page to see how much depends on your birth time, and the methodology page for how positions are computed.

Common misreadings

• "Rahu is exalted in Taurus." Or in Gemini; or it has no exaltation at all. BPHS, Sanketnidhi and the Bhrigu Sutras commentary give three answers, and BPHS's later chapters add more favoured signs.
• "Rahu is always bad." BPHS Ch. 47 Sl. 34-39 lists a favourable Rahu Dasha at length, Ch. 34 Sl. 17 makes a node a Yoga Karaka under stated conditions, and five sources agree on the 3rd, 6th and 11th houses.
• "My Rahu is retrograde." Every Rahu is. The flag says nothing about one chart over another.
• "Rahu aspects the 5th, 7th and 9th." BPHS Ch. 26 gives special aspects to Saturn, Jupiter and Mars only. This app gives Rahu the 7th, which always falls on Ketu.
• "Rahu Kaal is when Rahu is strong." It is a weekday slice of daylight, the same for everyone in a city.
• "The app says my Rahu is testing, so it is afflicted." The app prints the testing line for every Rahu, because it assigns the nodes no dignity. It is a default, not a diagnosis.
• "Rahu rules Aquarius, so read the Aquarius house in its Dasha." BPHS Ch. 47 says Aquarius, some sages say Virgo, the Bhrigu Sutras commentary says neither. This app shows no lordship themes for Rahu.
• "Rahu Mahadasha is eighteen hard years." Ch. 55 splits it into nine sub-periods of 10.8 to 36 months, each judged by its own lord's placement from the ascendant and from Rahu.

Questions people ask about Rahu

Is Rahu a real planet?

No. It is the ascending node of the Moon: the point where the Moon's orbit crosses the Sun's apparent path going north. BPHS still counts it among the nine grahas (Ch. 3 Sl. 10), and Bhrigu Sutras calls it a shadowy planet whose position can be computed but not observed.

Where is Rahu exalted and debilitated?

It depends on the book. BPHS Ch. 47 Sl. 34-39 says exalted in Taurus, which puts its debilitation in Scorpio. Bhrigu Sutras reports Sanketnidhi as exalting it in Gemini. This app assigns Rahu no dignity at all.

Is Rahu always retrograde?

Yes. The nodes move backwards at about 19.3 degrees a year. BPHS Ch. 47 Sl. 3-4 calls Rahu and Ketu always retrograde and times their Dasha results in reverse order through the sign.

How long is the Rahu Mahadasha, and who is born into it?

Eighteen years, the third-longest of the nine. A birth with the Moon in Ardra, Swati or Shatabhisha begins in it, part-way through. The Rahu Mahadasha page covers its nine sub-periods.

Is Rahu good in the 3rd, 6th or 11th house?

The sources agree that it is at its best there: Saravali Ch. 12, BPHS Ch. 48 and Ch. 55, Bhrigu Sutras and Chatterjee all say so in their own terms. Several add the condition that a benefic aspects it.

Why does this app show a testing line for my Rahu when the texts sound favourable?

Its favourable line needs a strong dignity, and the engine gives Rahu none because the texts disagree on what its dignities are. Every Rahu therefore gets the testing line. Use the house and company rules on this page to read your own.

Does this app use the mean node or the true node?

The mean node, everywhere. The two differ by at most about 1.88 degrees, which across 1950 to 2049 put Rahu in a different sign on 3.2% of days. The Kaal Sarp calculator reports the true-node offset for your birth moment.

How long does Rahu stay in one sign?

About 566 days on this engine's figures, moving backwards through the zodiac. It is in Aquarius until 6 December 2026 and then in Capricorn until June 2028. The Gochar calculator shows where that falls from your Moon.

What is Rahu Kaal, and does it depend on my chart?

It does not. It is one eighth of the daylight, fixed by the weekday and by local sunrise and sunset. The Rahu Kaal calculator works from a date and a place, with no birth details.