Horary Chart Calculator

A horary chart calculator answers a different kind of question from a birth chart calculator. A birth chart is cast for the moment of birth. A horary chart, called a Prashna chart in Vedic astrology, is cast for the moment a question is asked: the exact date, the exact time, and the exact place where the question was formed. The chart of that moment becomes the map the astrologer reads, with the rising sign at that moment, the question ascendant, standing for the querent and the question itself. This free calculator casts that chart for you, using real astronomy: the sidereal longitudes of the Sun, Moon, Mars, Mercury, Jupiter, Venus, Saturn, Rahu and Ketu, the sidereal question ascendant and midheaven, and the whole-sign houses counted from the rising sign, with the ascendant lord and the Moon highlighted as the traditional Prashna significators.

The calculation is deterministic and transparent. Your question date, question time, and place become a single UTC instant; each planet’s sidereal longitude is computed with a standard low-precision planetary theory minus the Lahiri ayanamsa; local sidereal time from the Julian day and the place longitude gives the rising ecliptic longitude, which minus the ayanamsa is the sidereal ascendant; and the whole-sign houses follow by counting signs from the ascendant. The tool loads with a worked example already rendered, so you can inspect real numbers before typing anything, and it states its framing openly: this tool computes the chart of the moment, and it does not predict an outcome.

What is a horary chart (Prashna chart)

Prashna Shastra is the Vedic branch of horary astrology, the art of answering a specific question from the chart of the moment it is asked. Classical sources for the method include the Brihat Parashara Hora Shastra and Prashna Marga, a text devoted to Prashna. The tradition is used when birth details are unknown, when a question is urgent, or when a querent wants a focused reading on one matter rather than a full life reading: will I get this job, will I get married this year, will my illness be cured, will I recover my money, will I travel abroad. The question chart does not replace the birth chart; it answers a different question, at a different moment.

The casting rule is simple and strict: take the exact time and place when the question is asked, and prepare the chart based on this moment. That is why this calculator asks for the question time and the question place rather than birth details. A question asked at 14:30 in Delhi and the same question asked at 14:30 in London are two different charts, because the rising sign depends on longitude and latitude, and the planets depend on the UTC instant. A rounded or guessed time gives a different chart, because the ascendant moves about 1 degree every 4 minutes. If you do not know the exact moment a question was first formed, use the moment you are asking now, and read the chart as the chart of that moment.

Two placements carry the traditional reading. The Lagna, or ascendant, of the Prashna chart represents the querent and their question, and a strong Lagna lord is traditionally read as supporting a favorable outcome, while a weak or afflicted Lagna shows difficulty. The Moon signifies the mental state of the querent: tradition reads a Moon in a Kendra (1st, 4th, 7th, 10th house) as confidence and a clear answer, a Moon in a Trikona (5th, 9th house) as moderate success, and a Moon in a Dusthana (6th, 8th, 12th house) as delay, confusion, or loss. This calculator highlights exactly those two significators, the ascendant lord and the Moon, with their signs, degrees, and whole-sign houses, so the traditional starting point of a Prashna reading is visible at a glance.

The rest of the reading follows the houses. Each kind of question belongs to a house: marriage to the 7th, career to the 10th, health to the 6th, finance to the 2nd and 11th, travel to the 9th and 12th, court cases to the 6th and 8th, a missing person to the 4th and 8th. The astrologer checks the strength of that house, its lord, and the planets placed in it, together with the applying and separating aspects between the Lagna lord and the house lord, the classical Ithasala and Isarapha yogas. This calculator gives you the whole-sign house map on which that reading is built: every planet’s house, every house’s sign and lord, and every house’s occupants, computed from the ascendant sign.

One honest framing note before you use the tool. The astronomical half of this page is computed with real orbital mechanics and checked against published data: the planetary longitudes, the Lahiri ayanamsa, the sidereal time, and the ascendant arithmetic are all verifiable numbers. The interpretive half, what it means for a question when the ascendant lord sits in the 11th house or the Moon sits in the 9th, belongs to astrology’s symbolic language, transmitted for centuries in the Jyotish tradition. Take what resonates, hold it lightly, and enjoy the precision of the calculation underneath it. Nothing here promises an answer to your question, and no single placement decides a matter on its own.

How to use this calculator

1. Enter the question date. Pick the year, month, and day the question was asked. Dates from 1900 to 2100 are accepted.
2. Enter the question time exactly. Use the 24-hour clock, hour and minute. The ascendant moves about 1 degree every 4 minutes, so an approximate time gives an approximate chart. There is no fallback for an unknown time: a horary chart without an exact moment is not a horary chart.
3. Choose the place where the question was asked. Pick the nearest city from the dropdown, or choose Custom place and type the latitude, longitude, and UTC offset. Place is required, because the ascendant cannot be computed without latitude.
4. Check daylight saving. City offsets are standard, non-daylight times. If the place observed summer time on the question date, choose Custom place and enter the offset that was actually in force, for example UTC+1 for a summer question in London rather than UTC+0.
5. Press Cast my horary chart. The tool converts your question time to UTC, computes the nine sidereal longitudes, derives local sidereal time from the Julian day and the place longitude, and finds the sidereal ascendant, midheaven, and whole-sign houses.
6. Read the spotlight. Your question ascendant with its degree and lord, the ascendant lord’s placement, the Moon’s placement, the midheaven, the ayanamsa, and the local sidereal time are summarized at the top.
7. Walk the tables. The planet table gives every graha’s sidereal position, whole-sign house, and sign lord; the twelve-sign grid shows which planets share each sign with its house number and the ascendant marker; and the twelve-house table lists every house with its sign, lord, and occupants.
8. Copy or print your result. The copy button saves a plain-text summary for your notes, and the print button produces a clean black-and-white version.

How this calculator computes your horary chart

The calculation starts by turning your question details into a single astronomical instant. Your question date, question time, and UTC offset are combined into a UTC timestamp, which becomes a day number d on the standard scale where d = 0 is 2000 Jan 0.0 UT, and a Julian day JD = d + 2451543.5. The Lahiri ayanamsa for that instant is ayanamsa = 23.85696 + (JD – 2451545.0) / 36525 x 1.396971 degrees.

Planetary positions come from the standard low-precision planetary theory: geocentric tropical longitudes for the Sun, Moon, Mercury, Venus, Mars, Jupiter and Saturn are computed from their orbital elements with the usual perturbation terms, then the Lahiri ayanamsa is subtracted to give the sidereal longitudes used in Vedic astrology. Rahu is the mean lunar node, node = 125.1228 – 0.0529538083 x d degrees tropical minus the ayanamsa, and Ketu sits exactly opposite at Rahu + 180 degrees. This is the same verified engine core used across our Vedic calculators, accurate to a few arcminutes, which is ample for sign and house work but not ephemeris grade.

The question ascendant is the ecliptic longitude rising on the eastern horizon at the question place and moment. First, Greenwich mean sidereal time comes from the Julian day: GMST = 280.46061837 + 360.98564736629 x (JD – 2451545.0) + 0.000387933 x T squared – T cubed / 38710000 degrees, where T is Julian centuries since J2000.0. Local sidereal time, also called RAMC, is GMST plus the place longitude, east positive. With RAMC, latitude, and the mean obliquity of the ecliptic (about 23.4393 degrees, decreasing slowly with T), the tropical ascendant follows from the closed form tan(ascendant) = cos(RAMC) / (-(sin(RAMC) x cos(obliquity) + tan(latitude) x sin(obliquity))), resolved with atan2 so the quadrant is correct for every latitude, north or south. The tropical midheaven follows from tan(midheaven) = sin(RAMC) / (cos(RAMC) x cos(obliquity)), also resolved with atan2. Subtracting the ayanamsa from each gives the sidereal, or nirayana, ascendant and midheaven, exactly as the classical rule prescribes: the computed ascendant is the sayan value, and subtracting ayanamsa gives the nirayana value.

The test suite verifies that closed form independently, not just by trusting it. For each test case, a brute-force scan walks every ecliptic longitude in 0.01-degree steps, computes the altitude of that ecliptic point at the given sidereal time and latitude, and finds the rising horizon crossing, the longitude whose altitude is zero and increasing into the sky. The closed-form ascendant matches that brute-force crossing to within 0.02 degrees in every case, including a southern-latitude case (Sydney), an equatorial case, and a high-latitude case (60 degrees north). A second check confirms the midheaven directly: the right ascension of the computed midheaven point equals RAMC, as it must for a point on the meridian.

Whole-sign houses then follow by counting signs. The whole rising sign is the 1st house, the next sign is the 2nd house, and so on around the zodiac, wrapping past Pisces back to Aries. A planet’s house is therefore house = ((planet sign index – ascendant sign index) mod 12) + 1, where sign indices run Aries 0 through Pisces 11. The house lord is simply the traditional lord of that house’s sign: Aries Mars, Taurus Venus, Gemini Mercury, Cancer Moon, Leo Sun, Virgo Mercury, Libra Venus, Scorpio Mars, Sagittarius Jupiter, Capricorn Saturn, Aquarius Saturn, Pisces Jupiter. This scheme uses the seven classical planets plus the two nodes as planets, and it does not use the outer planets as sign lords.

Worked example

Here is a worked example so you can see exactly what the tool computes. The tool loads with this example ready: question asked on August 24, 1995, at 14:30, in Delhi, India (latitude 28.6139 north, longitude 77.2090 east, UTC+5:30).

First the time conversion. 14:30 at UTC+5:30 is 09:00 UTC on August 24, 1995, which is day number d = -1589.625 and Julian day 2449953.875. The Lahiri ayanamsa for that instant is 23.7961 degrees. Local sidereal time for Delhi is 184.3815 degrees, and the mean obliquity is 23.4399 degrees. The engine’s sidereal longitudes are: Sun 126.9493 (Leo 6.95), Moon 105.8181 (Cancer 15.82), Mars 177.1447 (Virgo 27.14), Mercury 149.6369 (Leo 29.64), Jupiter 222.4309 (Scorpio 12.43), Venus 127.8805 (Leo 7.88), Saturn 329.1026 (Aquarius 29.10), Rahu 185.5034 (Libra 5.50), Ketu 5.5034 (Aries 5.50). The Moon’s sidereal longitude, 105.8181, is the established cross-check value from the earlier D10 and D60 builds for this same instant, which confirms that the shared engine is reproducing its verified numbers.

Now the ascendant, worked by the formula. The tropical ascendant from RAMC 184.3815 degrees, latitude 28.6139, and obliquity 23.4399 is 261.6181 degrees; subtracting the ayanamsa 23.7961 gives the sidereal ascendant 237.8220 degrees, which is Scorpio 27.82. The sidereal midheaven is Virgo 10.98. The ascendant lord is Mars, ruler of Scorpio, and Mars stands in Virgo 27.14. Counting whole-sign houses from Scorpio: Scorpio is house 1, Sagittarius 2, Capricorn 3, Aquarius 4, Pisces 5, Aries 6, Taurus 7, Gemini 8, Cancer 9, Leo 10, Virgo 11, Libra 12. So the ascendant lord Mars in Virgo sits in house 11, and the Moon in Cancer sits in house 9. You can check the house arithmetic directly: Virgo is sign index 5, Scorpio is sign index 7, and (5 – 7) mod 12 + 1 = 11; Cancer is sign index 3, and (3 – 7) mod 12 + 1 = 9.

The full house map is: house 1 Scorpio, lord Mars, holding Jupiter; house 2 Sagittarius, lord Jupiter, empty; house 3 Capricorn, lord Saturn, empty; house 4 Aquarius, lord Saturn, holding Saturn; house 5 Pisces, lord Jupiter, empty; house 6 Aries, lord Mars, holding Ketu; house 7 Taurus, lord Venus, empty; house 8 Gemini, lord Mercury, empty; house 9 Cancer, lord Moon, holding the Moon; house 10 Leo, lord Sun, holding the Sun, Mercury, and Venus; house 11 Virgo, lord Mercury, holding Mars; house 12 Libra, lord Venus, holding Rahu. In traditional Prashna terms, the two significators are therefore Mars in the 11th house and the Moon in the 9th house: the querent’s significator in the house of gains and fulfillment of hopes, and the mind’s significator in a Trikona, traditionally read as moderate success and clarity. That is the classical starting point for the reading, offered here as symbolism for reflection. The chart itself answers nothing on its own; a full reading would weigh the house of the matter asked about, its lord, and the aspects between the significators, as the method section above describes.

How to read your result

Your result has four parts. First, the spotlight: your question ascendant with its degree and lord, the ascendant lord’s sign, degree, and house, the Moon’s sign, degree, and house, the midheaven, the ayanamsa, and the local sidereal time. Start here, because tradition starts here: the ascendant is the querent and the question, its lord carries the querent’s strength, and the Moon carries the querent’s mind.

Second, the planet table: all nine grahas with their sidereal sign and degree, whole-sign house, and sign lord. Read down the house column to see which houses carry planets and which stand empty. Empty houses are not bad; they simply carry no planetary tenant at this moment, and their lords still speak for them. Then read the lord column: a planet’s sign lord tells you which planet rules the sign it occupies, the first step toward judging dignity and reception.

Third, the twelve-sign chart grid: a visual map of which planets fall in each sign, with each sign’s whole-sign house number and the ascendant marker showing the exact rising degree. This grid is the quickest way to see the shape of the question chart at a glance, and to compare it against another question chart or against a birth chart.

Fourth, the twelve-house table: every house with its sign, lord, and occupants. Find the house of the matter you asked about, marriage 7th, career 10th, health 6th, finance 2nd and 11th, travel 9th and 12th, court cases 6th and 8th, a missing person 4th and 8th, and read that house together with the two significators. Tradition then weighs dignity (a planet in its own sign, exaltation, or friendly sign), the applying or separating aspect between the Lagna lord and the house lord, and the Moon’s condition, before any judgment is offered. This calculator supplies the computed map; the judgment belongs to the astrologer and the querent, and any single placement read alone will mislead.

What this calculator does not do

Honest limits, stated plainly. This tool does not predict an outcome: it computes the chart of the moment of the question, and the ascendant, its lord, and the Moon are shown as traditional significators for reflection, not as verdicts. It uses a low-precision planetary engine, accurate to a few arcminutes, which is ample for signs and whole-sign houses but not ephemeris grade; within a few arcminutes of a sign boundary, a high-precision ephemeris could disagree on the sign. It uses whole-sign houses only: it does not compute Placidus, Koch, or other quadrant house cusps, and the midheaven shown is informational, not a house cusp in this system. It requires an exact question time and place: there is no noon fallback and no estimated ascendant, because a horary chart without an exact moment is not a horary chart, and the ascendant moves about 1 degree every 4 minutes. Rahu and Ketu are the mean nodes, not the true osculating nodes; the two differ by up to about 1.5 degrees, which can matter near a sign boundary. City offsets are standard times without daylight saving, so a question asked under summer time needs the custom offset that was actually in force. Finally, nothing here is a prediction of fate: a chart of a moment is a map for reflection and for a structured conversation, and the same chart read by two astrologers may be weighed differently, as tradition itself expects.

Frequently asked questions

What is a horary chart in Vedic astrology?

A horary chart, called a Prashna chart in Vedic astrology, is a chart cast for the exact moment a question is asked, using the question date, time, and place, instead of a birth date, time, and place. Classical sources for the method include the Brihat Parashara Hora Shastra and Prashna Marga. The rising sign at that moment, the question ascendant, represents the querent and the question, and the chart is read for that one matter rather than for a whole life.

Why does a horary chart need the exact time and place of the question?

Because the ascendant depends on both. The ascendant is the ecliptic longitude rising on the eastern horizon at the place and moment, so it changes with longitude and latitude, and it moves about 1 degree every 4 minutes as the Earth turns. A rounded time or a missing place gives a different ascendant, different houses, and therefore a different chart. This calculator requires an exact question time and a place with latitude for exactly this reason, and it offers no estimated ascendant.

What is the question ascendant in a horary chart?

The question ascendant is the sidereal sign and degree rising on the eastern horizon at the moment and place the question was asked. It is computed from local sidereal time, the place latitude, and the obliquity of the ecliptic, then converted from tropical to sidereal by subtracting the Lahiri ayanamsa. In traditional Prashna reading the ascendant represents the querent and the question itself, and its lord is the querent’s chief significator.

Why are the ascendant lord and the Moon highlighted?

Because tradition treats them as the two chief significators of a Prashna chart. The ascendant lord carries the querent’s strength: a strong Lagna lord traditionally supports a favorable outcome, while a weak or afflicted one shows difficulty. The Moon signifies the mental state of the querent: tradition reads a Moon in a Kendra as confidence and a clear answer, a Moon in a Trikona as moderate success, and a Moon in a Dusthana as delay, confusion, or loss. This calculator highlights both placements, with sign, degree, and whole-sign house, so the traditional starting point of the reading is visible at once.

What are whole-sign houses?

Whole-sign houses are the house system used in this calculator: the whole rising sign is the 1st house, the next sign is the 2nd house, and so on around the zodiac, wrapping past Pisces back to Aries. A planet’s house is therefore decided by its sign alone: house equals the planet sign index minus the ascendant sign index, wrapped to 0 to 11, plus 1. This system needs no intermediate house cusps, which is why the midheaven shown on the result page is informational rather than a house cusp.

Does this horary chart calculator predict the answer to my question?

No. This calculator computes the chart of the moment of your question: the sidereal ascendant, the nine sidereal planets, and the whole-sign houses, with the traditional significators highlighted. It does not predict an outcome, and nothing on the result page is a guaranteed answer. A full Prashna reading weighs the ascendant, its lord, the Moon, the house of the matter asked about, its lord, and the aspects between them, and that judgment belongs to the astrologer and the querent, used for reflection rather than as a verdict.

Is this horary chart calculator free?

Yes, it is completely free and no account or signup is needed. Enter the question date, the exact question time, and the place where the question was asked to get the sidereal ascendant and midheaven, the nine sidereal planets with their whole-sign houses, and the twelve-house table. Use the copy button to save your result as plain text.

Related tools

• D10 chart calculator: map the same nine sidereal planets into the ten Dasamsa divisions, the career layer that a job question in a horary chart often points toward.
• Sidereal natal chart: cast the full sidereal birth chart, the life map that a question chart is read alongside when birth details are known.
• Houses astrology calculator: explore the twelve houses and their meanings, the framework that assigns every horary question to its house.

About the author

This horary chart calculator was built by Saba for ZodiaScope. Saba builds astronomy-accurate astrology tools alongside traditional interpretations: the planetary longitudes on this page are computed with a standard planetary theory minus the Lahiri ayanamsa, the question ascendant follows from local sidereal time, latitude, and obliquity by a closed form verified against brute-force horizon search, and the whole-sign houses count from the rising sign, while the ascendant lord and the Moon are highlighted as the traditional Prashna significators exactly as the classical method prescribes. Interpretations are offered for reflection and entertainment.

Published: October 26, 2026. Last updated: October 26, 2026.