Find Your
Part of Fortune
Enter your birth date, time and place to get the sign, degree and house of your Part of Fortune, worked out with the day or night formula your chart calls for.
Day or Night Sets the Formula
The Part of Fortune uses one formula when the Sun is above the horizon at birth and the reverse when it is below. The calculator works out which applies from your birth time and place, so an exact time matters most for births near sunrise or sunset.
⊕What the Calculator Returns
Sign and Degree
Where the Part falls in the zodiac, to the minute of arc.
Day or Night Formula
Whether the Sun was above the horizon, and the formula that follows.
Whole Sign House
The house the Part occupies, counted from your rising sign.
Sign Reading
The kind of livelihood the sign points to, and its ruling planet.
Common Pitfalls
Where the placement usually loses ground.
Practical Steps
What to do with it, including which planet to check.
What Is the Part of Fortune?
The Part of Fortune is a point in the birth chart calculated from three positions: the Ascendant, the Sun and the Moon. It is the best known of the lots, the calculated points of Hellenistic astrology, and its formula already appears in Dorotheus of Sidon in the first century CE.
Its Greek name, klēros tēs tychēs, means the lot of fortune; medieval Latin translators called it pars fortunae, which became the English Part of Fortune. Unlike a planet, it has no body in the sky: it is a degree of the zodiac found by addition and subtraction. Vettius Valens tied it to the body and to the work of one's hands, and Ptolemy judged a person's wealth from the planets that govern it.
This Lot of Fortune calculator returns three things: the sign and degree of the Part; the house it falls in, counted in Whole Sign houses; and whether your chart is a day or a night chart, which decides the formula. The next section sets out the arithmetic, and the worked example after it runs the numbers on a real chart.
How the Part of Fortune Is Calculated
The calculation uses ecliptic longitude: each position counted from 0° Aries around to 360°, with Aries starting at 0°, Taurus at 30°, Gemini at 60° and so on to Pisces at 330°. There are two formulas, and which one applies depends on the chart's sect, whether the Sun was above or below the horizon at birth.
☀️ Day Chart Formula
Sun above the horizon at birth:
Ascendant + Moon − SunMeasure the arc from the Sun forward to the Moon, then count the same arc forward from the Ascendant.
🌙 Night Chart Formula
Sun below the horizon at birth:
Ascendant + Sun − MoonMeasure the arc from the Moon forward to the Sun, then count the same arc forward from the Ascendant.
If the total comes to 360° or more, subtract 360°; if it is negative, add 360°. The result is then read back as a sign and degree: a total of 400° becomes 40°, which is 10° Taurus.
Deciding Day or Night
A chart is a day chart when the Sun is above the horizon. The calculator judges this from the true Ascendant–Descendant axis: the Sun is above the horizon when its longitude lies in the half of the zodiac that runs from the Descendant degree forward through the Midheaven to the Ascendant degree. Whole-sign houses are not used for this, because the sign holding the Descendant is split by the horizon, so a Sun in the 7th whole-sign house can be on either side of it. The worked example below has exactly that case.
The Part's position and the day-or-night verdict both come from the same server calculation as the birth chart, so they use the same planetary positions. For the house, the calculator counts Whole Sign houses: the rising sign is the 1st house, the next sign the 2nd, and so on. The About page sets out the ephemeris and these conventions, and the sect calculator shows the day-or-night verdict on its own.
Two Things the Arithmetic Tells You
First, the Part sits as far from the Ascendant as the Moon is from the Sun: forward by day, backward by night. So its house tracks the Moon's phase at birth. Born near a New Moon, the Part lies close to the Ascendant; born near a Full Moon, close to the Descendant.
Second, the day and night results are mirror images across the Ascendant degree. They coincide near a New or Full Moon and fall 180° apart when the Moon is at a quarter, which is why getting the sect right matters more for some charts than others.
Worked Example: A Night Chart, Step by Step
Barack Obama was born at 7:24 PM on August 4, 1961, in Honolulu, the time on his birth certificate. That is 05:24 UTC on August 5, 1961. The positions below come from the same calculation the tool runs.
1. Day or night?
The Ascendant is 18°03′ Aquarius, so the Descendant, the degree setting on the western horizon, is 18°03′ Leo. The Sun, at 12°32′ Leo, is 5°31′ of longitude short of the Descendant, on the side below the horizon. It had set at 7:09 PM, 15 minutes before the birth, and at 7:24 PM its center was 4.2° below the horizon. This is a night chart. Note that Leo is the 7th whole-sign house here, one of the six usually drawn above the horizon; judging sect by whole signs would have called this a day chart.
2. Convert to longitude
Add each position to the longitude where its sign begins.
Positions in Barack Obama's chart converted to ecliptic longitude Point Position Sign begins Longitude Ascendant 18°03′ Aquarius 300° 318°03′ Sun 12°32′ Leo 120° 132°32′ Moon 3°21′ Gemini 60° 63°21′ 3. Apply the night formula
Ascendant + Sun − Moon = 318°03′ + 132°32′ − 63°21′ = 387°14′That is outside 0° to 360°, so subtract 360°, which leaves 27°14′. Aries runs from 0° to 30°, so the Part of Fortune is at 27°14′ Aries.
4. Count the house
In Whole Sign houses the rising sign, Aquarius, is the 1st house. Counting signs forward from it to Aries puts the Part of Fortune in the 3rd house.
What the day formula would have given
Ascendant + Moon − Sun = 318°03′ + 63°21′ − 132°32′ = 248°52′That is 8°52′ Sagittarius, in the 11th house instead of the 3rd. Both answers lie 69°11′ from the Ascendant, one on each side, and 69°11′ is the distance between the Sun and the Moon. Using the wrong sect would have moved the Part from Aries to Sagittarius.
A day chart at 9:03 PM: Prince William
Prince William was born at 9:03 PM on June 21, 1982, in London (20:03 UTC on June 21, 1982). The clock says evening, but the Ascendant was 27°28′ Sagittarius, so the Descendant was 27°28′ Gemini, and the Sun at 0°06′ Cancer was 2°38′ past it, still above the horizon. Sunset came 19 minutes later, at 9:22 PM; at the birth the Sun's center stood 1.4° above the horizon.
So the day formula applies, Ascendant + Moon − Sun, and the Part of Fortune falls at 2°20′ Capricorn, in the 2nd house. The night formula would have put it at 22°37′ Sagittarius, in the 1st. With the Moon at 4°57′ Cancer, only 4°51′ from the Sun, the two answers lie close together, yet they still fall in different signs and houses.
Sect follows the horizon, not the clock. Strictly, a chart turns from day to night when the Sun's center reaches the horizon, which that evening was 9:15 PM in London and, on Barack Obama's birthday, 7:05 PM in Honolulu. Published sunset times run a few minutes later because they track the Sun's upper edge and allow for refraction. For a birth within a few minutes of sunrise or sunset, trust the chart rather than a sunset table.
Positions are rounded to the nearest minute of arc, and the sums above use the rounded figures. The calculator works from unrounded positions, so adding the rounded figures can land 1′ away from its result. Sunset times and the Sun's altitude were computed with the site's ephemeris for each city's coordinates.
Fortune, Spirit, Jupiter and the Node
vs. the Lot of Spirit
The Lot of Spirit, Valens's Lot of Daimon, uses the same three positions with the Sun and Moon swapped: Ascendant + Sun − Moon by day, Ascendant + Moon − Sun by night. Valens assigned Fortune to the body and the work of the hands, Spirit to intellectual matters and to giving and receiving. Ptolemy's single formula gives, for a night birth, the point the reversing tradition calls Spirit.
vs. Jupiter
Jupiter is a planet that takes about 12 years to go around the zodiac, so people born within the same year or so share its sign. The Part of Fortune moves as fast as the Ascendant and goes through all twelve signs in about a day, so it depends on the birth time. In Ptolemy, Jupiter is one of the planets that can govern the Lot, not a stand-in for it.
vs. the North Node
The North Node is an astronomical point: where the Moon's orbit crosses the ecliptic heading north. It moves backward about 19° a year and stays in a sign for roughly 18 months. The Part of Fortune is a sum of three positions, with no counterpart in the sky.
Part of Fortune Through the 12 Signs
The sign shows the kind of livelihood the Part points to; the planet that rules the sign shows how well supported it is. Dorotheus and Valens both tell the reader to find the Lot's ruler and see where it stands, and Ptolemy tied five of the planets to particular sources of wealth. Each entry names the ruler and, where it applies, Ptolemy's line for it. The calculator above adds the house.
♈Fortune in Aries
Fortune in Aries
⊕ Earning by Going First
The Part of Fortune in Aries points to a livelihood built on initiative: starting the business, taking the first-mover role, doing work where speed and nerve count for more than seniority. Mars rules Aries, so Mars is the planet to read alongside the Part; its sign, house and aspects show how much support the placement gets. Ptolemy wrote that when Mars governs the Lot, wealth comes through military operations and command, which today covers any role where someone has to make the call. The Sun is exalted in Aries, and the placement tends to do best when the work carries your own name.
Where It Goes Wrong
The usual loss is the unfinished start: money and effort go into the next launch before the last one has paid.
♉Fortune in Taurus
Fortune in Taurus
⊕ Land, Goods and Slow Accumulation
The Part in Taurus points to income from things that hold their value: property, land, food, materials, well-made goods, and savings left alone long enough to grow. Venus rules Taurus, so her condition in your chart shows how easily the placement works. Ptolemy linked a Venus-governed Lot with wealth through gifts from friends or women, which reads today as money that arrives through goodwill and personal connections. The Moon is exalted in Taurus, and as a fixed sign it favors keeping an asset through its dull years over trading in and out.
Where It Goes Wrong
The placement stalls when security turns into hoarding: money kept idle out of worry, or a job or property held long after it stopped paying.
♊Fortune in Gemini
Fortune in Gemini
⊕ Trade, Talk and Brokering
The Part in Gemini points to a living made from words and exchange: writing, teaching, sales, translation, brokering, and work that moves information between people who would not otherwise meet. Mercury rules Gemini, and Ptolemy's line for a Mercury-governed Lot is wealth through eloquence and trade. Gemini is a double sign, and two income streams at once are common with this placement. Mercury's condition, especially whether it is retrograde or close to the Sun, shows how cleanly the exchanges go.
Where It Goes Wrong
The common loss is scatter: six projects started and none finished, or research that never turns into a sale.
♋Fortune in Cancer
Fortune in Cancer
⊕ Home, Food and the People You Keep
The Part in Cancer points to a livelihood tied to home and care: housing and property, food, hospitality, family businesses, and work that looks after people. The Moon rules Cancer, which gives the placement a feature it shares only with Leo: one of the three positions in the formula also rules the result, so the Moon's sign, phase and house carry extra weight. Ptolemy's list of planets that govern the Lot leaves out the Sun and Moon, so there is no line from him here. Jupiter is exalted in Cancer, and the traditional reading is generosity that comes back through family and household.
Where It Goes Wrong
The placement suffers when caring for others turns into running yourself down, or when income depends on one family relationship that cannot be renegotiated.
♌Fortune in Leo
Fortune in Leo
⊕ Recognition and Leading in Public
The Part in Leo points to a livelihood that depends on being seen: leading a team, performing, running a business under your own name, or any work where reputation is the main asset. The Sun rules Leo, so as with Cancer, one of the formula's own positions also rules the result; the Sun's house and aspects show where recognition comes from. Leo is a fixed fire sign, and its gains usually come from a long, consistent presence in one field rather than from a series of short bets.
Where It Goes Wrong
The placement falters when the work becomes a bid for approval rather than the work itself, or when credit is never shared with the people who did part of it.
♍Fortune in Virgo
Fortune in Virgo
⊕ Skill, Precision and Paid Expertise
The Part in Virgo points to income from competence: technical work, analysis, accounting, editing, health care, repair, and any trade where getting the details right is what the client pays for. Mercury both rules Virgo and is exalted in it, the only planet with its domicile and exaltation in the same sign, and Ptolemy's Mercury line applies as it does for Gemini: wealth through eloquence and trade. Virgo is a mutable earth sign, and the work tends to change form over the years while the skill underneath stays the same.
Where It Goes Wrong
The usual block is perfectionism: work held back because it is not finished enough, and prices kept low because the flaws are easier to see than the skill.
♎Fortune in Libra
Fortune in Libra
⊕ Partnerships, Contracts and Fair Terms
The Part in Libra points to income that comes through other people: business partners, clients, contracts, negotiation, mediation, and design work done for someone else. Venus rules Libra, so as with Taurus, Ptolemy's Venus line applies: wealth through gifts from friends or women, or in modern terms through goodwill and relationships. Saturn is exalted in Libra, which adds a condition: the arrangements that pay are the ones with clear, fair terms written down.
Where It Goes Wrong
The placement goes wrong when keeping the peace wins over fair terms, so you stay in a lopsided deal because renegotiating feels rude.
♏Fortune in Scorpio
Fortune in Scorpio
⊕ Persistence, Risk and Hard Problems
The Part in Scorpio points to income from work most people avoid: investigation, surgery, risk, debt and recovery, research, and crisis jobs where staying calm under pressure is the qualification. Mars rules Scorpio in the traditional scheme, and Ptolemy's line for a Mars-governed Lot is wealth through military operations and command; modern astrologers add Pluto as co-ruler. Scorpio is a fixed water sign, and the gains usually come from long persistence on one hard problem rather than from quick wins.
Where It Goes Wrong
The placement stalls when the need for control blocks every joint venture, or when secrecy keeps away the partners and backers the work needs.
♐Fortune in Sagittarius
Fortune in Sagittarius
⊕ Teaching, Law and Distance
The Part in Sagittarius points to a livelihood in teaching, law, publishing, religion, travel and foreign trade: work that carries ideas or goods across distances. Jupiter rules Sagittarius, and Ptolemy's line for a Jupiter-governed Lot is wealth through fiduciary relationships, guardianships and priesthoods, which is to say positions of trust. Sagittarius is a mutable fire sign, and the work tends to move between places, institutions or fields over a career.
Where It Goes Wrong
The usual loss is the plan that stays a plan: big promises, a new direction every year, and nothing carried far enough to pay.
♑Fortune in Capricorn
Fortune in Capricorn
⊕ Structure, Management and Long Horizons
The Part in Capricorn points to a livelihood built over decades: management, administration, building and construction, long-horizon finance, and positions that come with seniority. Saturn rules Capricorn, and Ptolemy's line for a Saturn-governed Lot is wealth through building, agriculture or shipping, the long-cycle businesses of his day. Mars is exalted in Capricorn, adding drive to the discipline. Results here tend to arrive late and last, so the placement is better judged over twenty years than over two.
Where It Goes Wrong
The placement stalls when status replaces substance: climbing a ladder chosen for the title, or working so hard there is no time to use what has been built.
♒Fortune in Aquarius
Fortune in Aquarius
⊕ Organizations, Systems and Networks
The Part in Aquarius points to income through groups and systems: organizations, associations, technology, infrastructure, and work that serves many people at once. Saturn rules Aquarius in the traditional scheme, so Ptolemy's Saturn line applies as it does for Capricorn: building, agriculture or shipping, the long-cycle work of his day. Modern astrologers add Uranus as co-ruler and tie the sign to technology through it. Aquarius is a fixed air sign, and the placement rewards staying with one network or institution long enough to shape it.
Where It Goes Wrong
The placement stalls when distance becomes a habit: watching the group from outside, criticizing it, and never staying long enough to have a say.
♓Fortune in Pisces
Fortune in Pisces
⊕ Care, Art and Positions of Trust
The Part in Pisces points to a livelihood in care and imagination: health and social care, music and the arts, religious or charitable institutions, and work done out of sight for others. Jupiter rules Pisces in the traditional scheme, so Ptolemy's Jupiter line applies: wealth through fiduciary relationships, guardianships and priesthoods, or positions of trust. Venus is exalted in Pisces, and modern astrologers add Neptune as co-ruler. Pisces is a mutable water sign, and income here often comes indirectly, through institutions or patrons rather than direct sales.
Where It Goes Wrong
The placement suffers when giving has no limit: unpaid work, loans that are never repaid, or a role where everyone else's needs come first.
Sources: Dorotheus, Valens, Ptolemy and the Arabic Parts
Dorotheus of Sidon, a first-century astrologer whose poem survives mainly in an Arabic translation, gives the rule in Book I, chapter 26 of the Carmen Astrologicum (David Pingree's translation): by day, count from the Sun to the Moon and add the Ascendant; by night, the opposite.
Vettius Valens, writing in the second century, gives the day count from the Sun to the Moon in Book II of his Anthology, reverses the luminaries by night (as the example charts in the same book show), and treats the Lot as a second Ascendant: the Lot itself stands for life and the tenth place from it for rank.
Ptolemy, in the Tetrabiblos, uses the Sun-to-Moon distance by day and by night alike (Book III, chapter 10, on the length of life, in F. E. Robbins's Loeb translation). His reason is that the Moon should then stand to the Lot as the Sun stands to the Ascendant, making the Lot, in Robbins's words, “as it were a lunar horoscope.” In Book IV, chapter 2, he judges wealth from the planets that govern the Lot.
The Arabic Parts. Medieval Latin translations of Arabic astrology called the lots partes, so the Lot of Fortune became pars fortunae, the Part of Fortune. Because they reached Europe through Arabic books, the lots are still often called the Arabic Parts, though they are Greek in origin.
The disagreement never closed. Following Ptolemy, some astrologers and programs use the day formula for every chart, so a night birth can get a different Part elsewhere. This calculator follows Dorotheus and Valens and switches formulas by sect.
Frequently Asked Questions
What is the Part of Fortune in astrology?
The Part of Fortune, also called the Lot of Fortune (Latin pars fortunae), is a point in the birth chart calculated from the Ascendant, the Sun and the Moon. It is not a planet but a degree of the zodiac found by addition and subtraction. Hellenistic astrologers read it for the body, livelihood and material circumstances, and Ptolemy judged wealth from the planets that govern it.
How is the Part of Fortune calculated?
With ecliptic longitudes from 0° to 360°: by day, Ascendant + Moon − Sun; by night, Ascendant + Sun − Moon, adding or subtracting 360° to bring the result into range. A chart is a day chart when the Sun is above the horizon, judged from the true Ascendant–Descendant axis. For Barack Obama, born after sunset, the night formula gives 318°03′ + 132°32′ − 63°21′ = 387°14′, which is 27°14′ Aries.
Which house is my Part of Fortune in?
The calculator counts Whole Sign houses: the sign rising at birth is the 1st house, the next sign the 2nd, and so on around the zodiac. The house shows which area of life the Part's matters concern, such as the 2nd for money and possessions, the 7th for partners and the 10th for career. In a quadrant system such as Placidus the same degree can fall in the neighboring house, so the house can differ from other programs while the sign and degree match.
Why does another program give me a different Part of Fortune?
Usually because of the night formula. Ptolemy used the day formula for every chart, and some programs still do, which changes the result for anyone born at night. The house system can also differ, as can the birth time entered: the Part moves with the Ascendant, on average about 1° every four minutes.
Does the Part of Fortune need an exact birth time?
Yes. Because it moves with the Ascendant, an error of half an hour can shift it by around 7°, often into the next sign and house. Near sunrise or sunset a few minutes can also switch the chart between day and night, which mirrors the Part across the Ascendant: in Barack Obama's chart that is the difference between 27°14′ Aries and 8°52′ Sagittarius. Use the time on a birth certificate or hospital record when you have one.
Is the Part of Fortune one of the Arabic Parts?
Yes, the best known of them. "Arabic Parts" is a later name for the lots of Hellenistic astrology, which reached medieval Europe through Arabic books and were called partes in Latin. Valens calls the Lot of Fortune the most influential of them, and he builds others, such as the Lot of Spirit, from the same positions or from the Lot of Fortune itself.
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Complete the Picture
The Part of Fortune is read with its ruling planet and with the Sun, Moon and Ascendant it comes from. The full birth chart shows all of them.
Full Birth Chart