Free Birth Chart Calculator

The form above casts the chart. This section is its manual. It walks the result from top to bottom and says for each panel which classical rule it rests on, what the server actually does to produce it, and how far it can be trusted when the birth details are incomplete. One real chart, cast with this engine on 5 October 2026, runs through the page, so every number here can be reproduced by typing the same details into the form. Where the engine reads a rule more loosely than the text it cites, that is said too.

What the texts mean by a kundli

Brihat Parashara Hora Shastra (BPHS, listed with the other texts on the sources page) defines the pieces in a few lines. The lights in the sky that do not move are the nakshatras, and the ones that travel through them are the grahas. The same circle is divided twice: into 27 nakshatras counted from Ashwini, and into 12 equal rashis counted from Mesha. The rashi rising in the east is the Lagna, and a person's results are worked out from the Lagna and from the grahas as they join and separate (Ch. 3 Sl. 2-6). A kundli is that frame filled in for one moment at one place.

The method follows in Ch. 3 Sl. 8-9. The grahas' positions are to be taken by Drikganit, computation that agrees with what is observed, and the Lagna found from the rising durations of the rashis at the birth place. The translator's note to that chapter gives the scale: a rashi needs roughly two hours to cross the horizon, so a degree takes about four minutes, depending on the latitude. That note is tested further down.

BPHS names nine grahas (Ch. 3 Sl. 10), and the engine computes all nine: Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn, Rahu and Ketu. Three consequences of those slokas shape this page:

• The grahas' positions are the same for everyone born at the same instant, anywhere on Earth. They need a date, a clock time and a time zone, but not a place.
• The Lagna belongs to the place. Without coordinates there is no rising sign to compute, and without a time there is no moment to compute it for.
• The nakshatra is a second, finer division of the same circle. The Moon's nakshatra at birth sets where the dasha starts.

From the form to one instant

Before any astronomy runs, the server turns what you typed into a single moment in universal time, plus a record of what was missing. A value that fails its check is refused with a message, not repaired into something plausible.

A typed place is looked up in a bundled list of cities first and, only if it is not there, sent to Open-Meteo's geocoding service. If neither finds it, the place is dropped and the result says it was not used. The engine never falls back to a default coordinate, because an Ascendant computed from an invented latitude would look exactly like a real one.

The time zone is a named zone, not a fixed number of hours. The offset applied is the one that zone used at the birth moment, so a July birth in London is read at UTC+1 and a January one at UTC+0. An hour's error can change the rising sign, and with whole-sign houses that puts every graha in the wrong house.

The worked chart on this page is 17 September 1983, 18:40, Indore. Indore is in the bundled list (22.7196 N, 75.8577 E, zone Asia/Kolkata), so the offset is UTC+5:30 and the instant the engine reads is 13:10 universal time. Nothing about the request is written to a database, and one connection may run 20 calculations a minute.

How the sky is computed for that instant

The engine does not use Swiss Ephemeris, and the methodology page says so plainly. It uses published closed-form methods, each with a stated accuracy in the code.

Those formulas give tropical longitudes, measured from the equinox. A Vedic chart is sidereal, measured against the stars, so the engine subtracts the Lahiri ayanamsa: 23.85306 degrees at the start of 2000, changing by 0.0139601 degrees a year. The publishers' note of Advanced Predictive Astrology says its author follows Lahiri only. For the worked chart the ayanamsa is 23.6256 degrees. The Sun's tropical longitude is 174.079 degrees, and after the subtraction it stands at 150.4536, which is 0.45 of a degree into Virgo. The ayanamsa calculator shows the value for any date.

Each sidereal longitude is then described the same way. The sign is the 30-degree slice it falls in, the nakshatra the slice of 13 degrees 20 minutes, and the pada a quarter of that. The nakshatra lord is read off the nine-lord Vimshottari cycle, which repeats three times round the 27 nakshatras. Houses are whole-sign: the rising sign is the 1st house from its first degree to its last, the next sign is the 2nd, and each graha takes the house of its sign. The page prints degrees and minutes, so a returned 8.54 appears as 8 degrees 32 minutes.

Reading the result, panel by panel

The sentence at the top

The one large sentence is composed by the engine from four values that also appear elsewhere in the result: the Lagna sign, the Moon's nakshatra, the title the numerology engine gives your Mulank, and the element that holds the most grahas. For the worked chart it reads: "Pisces Lagna with a Uttara Ashadha Moon gives you the strategist instincts, expressed through a water-dominant chart." Strategist is the title for Mulank 8. It summarises four cells and is only as firm as the least certain of them.

When there is no Lagna the engine switches to a second wording that opens with the Moon's nakshatra. That wording says the birth time is not set even when the time was given and it was the place that was missing. The panel underneath, not the sentence, is the accurate account of what was absent.

The three anchors

The Sun sign, the Moon sign and the Ascendant are the points other rules are counted from. Saravali builds one family of yogas on the signs either side of the Moon (Ch. 13) and another either side of the Sun (Ch. 14), and BPHS reads the houses from the Lagna. Each has its own calculator: Sun sign, Moon sign, nakshatra and Lagna.

The Sun sign here is sidereal, so it is often not the sign a Western column gives you. The gap is the ayanamsa, about 24 degrees in this era. For roughly the first 24 degrees of every tropical sign the sidereal Sun is still in the sign before; only in the last six or so do the two agree. The worked chart falls in that narrow band: its tropical Sun is 24.08 degrees into Virgo and its sidereal Sun 0.45 of a degree into Virgo, so both systems say Virgo, but only just.

The janma-nakshatra line

The line under the anchors is a temperament note keyed to the Moon's nakshatra and nothing else. There are 27, one per nakshatra, each set into the same frame. The engine's source note attributes them to the nakshatra chapter of Jyotisha-Siddhanta-Sara, paraphrased, and records three deliberate omissions: the caste classification that chapter attaches to each nakshatra is dropped entirely, appearance and marriage predictions are dropped, and a few harsh character verdicts are softened into tendencies. Read it as temperament, not as a forecast. Each nakshatra has its own article, for example Uttara Ashadha, and Moon sign and nakshatra explains how the two divisions relate.

The panel that says what the reading cannot say

The server attaches up to six limitation codes to a result, and the panel turns each into a sentence. The mechanism behind each tells you how seriously to take it.

The last code is measured, not asserted. When there is no birth time, the server runs the same engine twice more, at 00:00 and at 23:59 on the birth zone's clock, and compares the Moon. If the nakshatra and the sign are the same at both ends, the missing time cannot change them, and the panel says the nakshatra is certain. If they differ, it names both nakshatras. Two limits apply. A change of Moon sign that day is in the server's answer but not in the sentence. And only the Moon is checked: a Sun or a slow graha on a sign boundary is not flagged, as the worked chart shows below.

The other seven grahas

The ledger gives Mars, Mercury, Jupiter, Venus, Saturn, Rahu and Ketu a row each: sign, degree, nakshatra with pada, and dignity. Two small flags can sit beside a name.

• Retrograde. The engine computes the graha's longitude half a day before and half a day after birth; if it went backwards, the flag is set. Rahu and Ketu are always marked retrograde, the Sun and the Moon never.
• Combust. The graha is within a set distance of the Sun: Mars 17 degrees, Mercury 14 (12 when retrograde), Jupiter 11, Venus 10 (8 when retrograde), Saturn 15. The code cites S. Kannan's Fundamentals of Hindu Astrology for these limits. The Moon is tested too, at 12 degrees, but it sits in the anchor row, which prints no flags.

The dignity label says how a graha stands in its sign. The engine tests the conditions in the order of the table and stops at the first that fits. The number is the position-strength value the code attaches to each label, on a ladder it cites to Kannan.

Three details decide how to read that column. First, exaltation is tested by sign. BPHS also gives each graha a deepest degree of exaltation, but the label does not grade by distance from it. Second, the Moolatrikona bands come from Kannan, as the engine's header says, and differ from BPHS Ch. 3 Sl. 51-54 in one place: BPHS gives Venus the first half of Libra where the engine uses its last three degrees (the Sun's band was corrected to BPHS's first 20 degrees of Leo in October 2026). A Venus in those stretches can read Own sign here and Moolatrikona by Parashara's rule, or the reverse.

Third, friendship is not fixed. BPHS Ch. 3 Sl. 56 makes two grahas temporary friends when one stands in the 2nd, 3rd, 4th, 10th, 11th or 12th sign from the other, and Sl. 57-58 combine that with their natural relationship into five grades. The engine reads the temporary half from your chart, so the same graha in the same sign can be Friendly in one chart and Neutral in another. Rahu and Ketu get no dignity.

The strongest and weakest marks rank that one ladder across the seven grahas from the Sun to Saturn; ties go to whichever comes first in that order. They speak of sign dignity only. A fuller measure weighs direction, time, motion and aspect as well, and that is the Shad Bala calculator. Debilitated and weakest are grades of placement, not forecasts of events.

Element balance

BPHS names the element of each sign as it describes them: Mesha fiery, Vrishabha earthy, Mithuna airy, Karka watery (Ch. 4 Sl. 6-11), and the pattern repeats round the circle. The ledger's footer counts how many of the nine grahas, Rahu and Ketu included, stand in signs of each element; the Ascendant is not counted. Rahu and Ketu are always in opposite signs, and opposite signs are always a fire and air pair or an earth and water pair, so the nodes add one to each side of such a pair in every chart. The element named in the top sentence is the largest count; on a tie the first in the order fire, earth, air, water is taken.

Your running dasha

BPHS lists many dasha systems and calls Vimshottari the most appropriate for general use (Ch. 46 Sl. 2-5). The dasha lords run Sun, Moon, Mars, Rahu, Jupiter, Saturn, Mercury, Ketu, Venus, counted from Krittika, so the Moon's nakshatra at birth names the first lord (Sl. 12-14). Their periods are 6, 10, 7, 18, 16, 19, 17, 7 and 20 years, 120 in all (Sl. 15). The part of the first period already used up at birth is in proportion to how far the Moon has gone through its nakshatra (Sl. 16). What a Mahadasha is explains the idea.

The engine follows that rule with two choices of its own. It measures the Moon's progress by arc, the fraction of the 13 degrees 20 minutes already covered, where the sloka speaks of the time the Moon has spent in the nakshatra. And it counts a year as 365.2425 days. The sub-period follows BPHS Ch. 51 Sl. 1-2: an antardasha's length is the product of the two lords' years divided by 120, and the first antardasha belongs to the mahadasha's own lord. Dates are printed in your browser's time zone. The full sequence is on the Vimshottari dasha calculator, and the finer levels are covered in antardasha and pratyantar.

Yogas in your chart

A yoga is a named combination: a stated arrangement of grahas, signs and houses with a stated classical reading. The detector runs only when there is a Lagna, and it checks a fixed list. What a yoga in your chart means covers how much weight one deserves.

Two reading notes follow from the code. Exactly one Sankhya yoga applies to every chart, because the seven grahas must occupy between one and seven signs. A chart with a Lagna therefore always shows at least one card, and that card describes spread, not distinction. And several tests are simpler than their slokas. For Vesi, Vasi and Ubhayachari, BPHS Ch. 38 Sl. 4 says a malefic forming the yoga gives the contrary result; the engine lists the yoga whichever graha forms it. The yogas calculator lists every rule in full.

The twelve houses and the numbers

The house rail lists each house with its sign and the grahas in it. BPHS Ch. 11 Sl. 2-13 gives each bhava its subjects, from the body and appearance in the 1st to expenses in the 12th, and Sl. 14-16 give the first rule for judging one: a house joined or aspected by a benefic prospers, and one whose lord sits with a malefic suffers. Each house has an article, such as the 7th house or the 10th, and so does each graha in each house, such as Saturn in the 8th.

The numbers rail comes from the calendar date alone, exactly as typed, so a missing time or place never degrades it. Mulank is the day of the month reduced to one digit. Bhagyank is every digit of the full date added and reduced, with 11, 22 and 33 kept. Advanced Vedic Numerology gives both rules. The personal year is the birth day plus the birth month plus the current year, reduced to one digit, which that book calls the Western method. For the worked chart: 17 gives Mulank 8, the digits of 17-09-1983 add to 38 and then 11, and 17 + 9 + 2026 = 2052 gives personal year 9. The numerology calculator takes these further, and Mulank, Bhagyank and Life Path explains how they differ.

A worked chart: 17 September 1983, 18:40, Indore

This is what the server returned for those details on 5 October 2026. The precision panel reported no limitations.

The dignities can be checked by hand. Saturn in Libra and Mars in Cancer are the exaltation and debilitation signs of BPHS Ch. 3 Sl. 49-50. Jupiter is the instructive one. It sits in Scorpio, a sign of Mars, and Mars is Jupiter's natural friend. But Mars stands in Cancer, the ninth sign from Jupiter's, which is not one of the six friendly positions of Sl. 56, so the two are temporary enemies in this chart. A natural friend who is a temporary enemy comes out equal under Sl. 57-58, and the label reads Neutral. Mercury shows the opposite case: the Sun rules Leo, is Mercury's natural friend and stands in the second sign from it, so the label reads Friendly sign.

Mercury carries both flags. It was moving backwards across the day of birth, and it stood 3.50 degrees from the Sun, well inside the 12-degree limit for a retrograde Mercury.

The dasha, by hand

The Moon is at 278.5395 degrees. Uttara Ashadha runs from 266 degrees 40 minutes to 280 degrees and is the 21st nakshatra, whose lord in the cycle is the Sun. The Moon has covered 0.8905 of it, so 0.1095 of the Sun's six years remained at birth: 240 days, ending the first period on 14 May 1984. The Moon's ten years, Mars's seven and Rahu's eighteen follow, and Jupiter's sixteen run from 15 May 2019 to 15 May 2035 on the Indian calendar. That is the mahadasha the panel shows. Inside it the Ketu antardasha, 16 times 7 divided by 120 years or about 341 days, runs from 20 April 2026 to 27 March 2027. The articles on the Jupiter Mahadasha and the Saturn Mahadasha describe what the texts say of each.

The engine's arc method can be compared with the time method of BPHS Ch. 46 Sl. 16 on this chart. By this engine's own Moon, it entered Uttara Ashadha at 18:38 on 16 September and left at 21:38 on the 17th, a stay of about 27 hours, and the birth fell 24 hours and 2 minutes into it. That is 0.8902 by time against 0.8905 by arc, a difference of about half a day over the Sun's six years.

The five yoga cards

1. 1.Ubhayachari. Saturn is in Libra, the 2nd sign from the Sun, and Mercury in Leo, the 12th. This is Saravali Ch. 14 Sl. 1 exactly.
2. 2.Chandradhi (Adhi). Mercury is in the 8th sign from the Moon with no malefic in or aspecting its house. Saravali Ch. 35 Sl. 20-21 speaks of all the benefics there; one qualifies here, and the card calls it a modest version. The test does not weigh this Mercury being combust.
3. 3.Damini. The seven grahas occupy six signs, since Mars and Venus share Cancer. This is the Sankhya yoga every chart has one of (Saravali Ch. 21 Sl. 19).
4. 4.Vimala. Saturn rules Aquarius, the 12th house from Pisces, and stands in the 8th: the lord of one difficult house placed in another.
5. 5.Parivarthana. The Sun is in Mercury's sign and Mercury in the Sun's. Because the Sun rules the 6th house here, the card calls the exchange mixed.

What is absent is as informative. Saturn is exalted, but in the 8th house, not a kendra, so there is no Sasa Yoga: BPHS Ch. 75 Sl. 1-2 needs both. Jupiter is in the 11th sign from the Moon and the 9th house from the Lagna, a kendra from neither, so there is no Gaj Kesari. And the Sun, alone in the 7th, is the only graha in a kendra, so there is no Sarpa Yoga: BPHS Ch. 35 Sl. 8 asks for malefics in three kendras.

How much the birth details move this chart

The same engine was run again with parts of the input removed or shifted. With the date alone, the server returned five limitation codes: no time, no place, no Ascendant, time zone assumed and Moon boundary. The noon Moon stood at 5.25 degrees of Capricorn, pada 3 in place of 4, and the panel reported that it moved from Uttara Ashadha into Shravana that day.

The signs and dignities of the grahas did not change between the timed and the date-only reading: the same seven labels, the same strongest and weakest graha, the same element counts. That is the general shape of a reading without a birth time. The slow material is mostly solid; the Moon is checked; the Lagna, the houses and the yogas are absent, not estimated; and the dasha dates are approximate by months. What to do when the birth time is unknown goes through the options, and why apps disagree on your nakshatra explains differences between calculators.

What this page leaves out, and where it lives

The result above is the rashi chart and what follows directly from it. Other parts of a full kundli are computed elsewhere from the same engine.

• Divisional charts. The Navamsa (D9) and the other vargas each have a calculator, and Navamsa, the second chart explains why it is read beside this one.
• Doshas. Mangal dosha, Kaal Sarp and Sade Sati are separate checks, not part of the yoga list here.
• The present sky. Gochar reads today's transits from your Moon sign, and the timing feature combines them with the dasha.
• Two charts together. The kundli matching tool compares two Moon nakshatras by the eight kootas.
• The whole list. Every public calculator is on the calculators page, and the Kundali feature page describes what the saved chart adds.

Questions

Is this a Vedic chart or a Western one?

Vedic. Positions are sidereal, using the Lahiri ayanamsa, and houses are whole-sign from the Lagna: the rising sign is the 1st house in full, whatever the Ascendant's degree. Because of the ayanamsa your Sun sign here is often the sign before the one a Western chart gives.

I only know my date of birth. What can I rely on?

Every graha except the Moon moves a degree or two a day at most, so its sign is rarely affected, though the worked chart's Sun changed sign that morning. The Moon's nakshatra is reliable when the panel says the Moon stayed in one nakshatra all day. The dasha lords are usually right, but their dates can be off by months. The Ascendant, houses and yogas are not shown at all.

Why does the page show no Ascendant when it could estimate one?

A rising sign lasted between an hour and a half and two and a quarter hours in the chart measured above. An estimate without a time would usually be wrong and would look exactly like a real answer, so the server returns nothing and says why.

Are my birth details stored?

No. The request is computed and answered, and nothing is written to a database. The one outside call sends the place name, and only that, to Open-Meteo when it is not in the bundled list. The privacy page has the full statement.

Another site gives me a different nakshatra or dasha date. Which is right?

Check three things first: the ayanamsa (this engine uses Lahiri), the time zone applied to your birth, and the birth time itself. In the worked chart ten minutes of clock time moved every dasha boundary by nearly two weeks.

Does Debilitated or weakest graha mean something bad will happen?

No. They are grades of how a graha stands in its sign, on one ladder out of several. The texts weigh sign dignity together with house, aspect and timing before saying anything about results.