What the houses are
The houses are twelve divisions of the sky as seen from the place you were born, drawn from two lines: the horizon, where sky meets ground, and the meridian, the north–south line passing overhead. Each house stands for an area of life: money, relationships, work, home. A planet in your 7th house plays out mostly in your partnerships; the same planet in the 10th plays out in your career.
The easiest way to hold it in your head is a three-part sentence. The planets are what: Venus is affection, Mars is drive, Saturn is responsibility. The signs are how: Mars in Libra negotiates, Mars in Aries charges. The houses are where: that Mars in the 2nd house fights over money, in the 4th over family. Reading a chart, as we explain in how to read a birth chart, is putting the three together.
The key difference from signs is where they come from. The zodiac is fixed to the Sun and the seasons; houses are local, built from your own horizon. Two people born in the same minute, one in London and one in Los Angeles, have every planet in the same sign but in completely different houses.
One detail trips people up. Houses are numbered counterclockwise from the ascendant, but the daily turning of the sky carries everything through them clockwise. The Sun rises at the ascendant, climbs through the 12th, 11th and 10th houses to the midheaven at noon, sinks through the 9th and 8th to set at the descendant, and spends the night below the horizon in houses 6 down to 1. So your Sun’s house tells you roughly when you were born: a 12th-house Sun means within about two hours after sunrise; a 4th-house Sun, around midnight.
Why houses need an exact birth time
Because the houses make a full circuit of the sky every day. As the Earth turns, each house cusp sweeps through all 360° of the zodiac in about 24 hours, which works out to roughly 1° every 4 minutes on average. An hour’s error shifts the ascendant and the other cusps by about 15°, half a sign.
In practice, planetary signs survive an approximate birth time well (except the Moon, which covers about 13° a day), but houses do not. A planet 3° from a cusp can change house with a twelve-minute error. If your time comes from family memory (“sometime in the afternoon”), houses are the part of your chart to hold most loosely, and the part most worth checking against a birth certificate.
The calculation itself is the one behind the ascendant: local clock time, historical time zone, sidereal time and latitude. We walk through it step by step on the rising sign calculator page. The calculator above does all of it with the Swiss Ephemeris and the Placidus system, the same setup as your full birth chart.
The four angles, and angular, succedent and cadent houses
The angles are the four points where the horizon and the meridian cross the ecliptic, and they are the most important cusps in the chart. The ascendant (ASC) is the degree rising in the east and opens the 1st house. The imum coeli (IC) is the lowest point, beneath your feet, and opens the 4th. The descendant (DSC) is the degree setting in the west and opens the 7th. The midheaven (MC) is the highest point crossing the meridian and opens the 10th.
ASC and DSC are always exactly opposite, as are MC and IC. What is not fixed is the angle between the two axes: the MC is not necessarily 90° from the ascendant, and away from the equator it can be a long way from that. That is why houses in the same quadrant can differ so much in size, as the latitude section below shows.
The twelve houses fall into three groups of four according to where they sit relative to the angles. Angular houses begin at an angle and are the most visible: planets there show and act outward. Succedent houses follow and consolidate what the angular ones start: resources, stable bonds, things that accumulate. Cadent houses lead into the next angle and are houses of learning, adjusting and preparing.
| Type | Houses | Natural signs | Function |
|---|---|---|---|
| Angular | 1, 4, 7, 10 | Aries, Cancer, Libra, Capricorn | Start, act, be seen |
| Succedent | 2, 5, 8, 11 | Taurus, Leo, Scorpio, Aquarius | Build, sustain, accumulate |
| Cadent | 3, 6, 9, 12 | Gemini, Virgo, Sagittarius, Pisces | Learn, adjust, pass on |
The match is not a coincidence: angular houses line up with the cardinal signs, succedent with the fixed and cadent with the mutable. A planet close to an angle, especially within a few degrees of the ascendant or midheaven, usually carries much more weight than the same planet in a cadent house.
The 12 houses in astrology and their meanings
Each house has a “natural” sign and planet: the ones it would have if the ascendant sat at 0° Aries. That pairing helps you feel the tone of the house, but in your actual chart each cusp will fall in a different sign with a different ruler. For every house below you will find the areas it covers, what planets there tend to show, and what it means when the house is empty.
1st house: self, body and how you begin
The 1st house starts at the ascendant and stands for you as a person: your body, appearance and vitality, the temperament you bring to anything new, and the first impression you leave. Its natural sign is Aries and its natural ruler Mars, which gives it its starting-gun quality. This is the house of “here I am.”
Planets in the 1st house are on display. They don’t stay inside you; they become part of how you walk into a room. With the Sun here, identity and presence are one and the same, and it is hard for you to go unnoticed. With the Moon, your mood is written on your face. Mars brings physical energy, hurry and a bluntness that can read as aggression. Saturn makes the first impression serious or reserved, and many people with it feel more at home in their body as they age than they did when young.
The 1st house is never truly empty, because its cusp is the ascendant, which says a great deal on its own. If no planets are here, read the rising sign and especially its ruler: where that planet sits shows where your personal energy is headed. A Taurus rising with Venus in the 10th, for example, describes someone whose sense of self is built largely through work and public life.
Example: someone with Jupiter 4° from the ascendant tends to come across as larger than life, in presence or quite literally. The pull is toward expansion and optimism and, over the years, toward having to watch the portions. The full rising-sign guide is on the rising sign calculator page.
2nd house: money, possessions and what you value
The 2nd house covers your own resources: the money you earn, what you own, the talents you can put to use and, at a deeper level, what you value and how much you value yourself. Its natural sign is Taurus and its ruler Venus. As a succedent house, it turns the energy launched by the 1st into something you can hold.
Planets here describe how you earn and how you spend. Mars in the 2nd earns through effort and initiative and spends with the same impulse. Venus here appreciates beauty and comfort and often earns through art, people skills or taste. Saturn in the 2nd usually treats money as serious business: early insecurity, caution, and a slow build that with discipline becomes solid. Jupiter widens both income and the urge to spend it.
An empty 2nd house does not mean a lack of money or of interest in it; it means this is not where your chart concentrates its action. The sign on the cusp shows your style with resources (Virgo there budgets carefully; Sagittarius is generous and takes chances), and its ruler shows where money tends to come from. If your 2nd-house ruler sits in the 9th, income often links to teaching, travel, foreign work or publishing.
Example: the Moon in the 2nd brings income that rises and falls the way moods do, and an emotional need for material security. For this person a savings cushion is not a luxury; it is what lets them sleep at night.
3rd house: communication, siblings and your neighborhood
The 3rd house rules the everyday mind and everything close at hand: how you talk, write and learn, brothers, sisters and cousins, neighbors, early schooling, short trips, messages and your local area. Its natural sign is Gemini and its ruler Mercury. It is cadent: a house of learning and exchange. A 3rd-house emphasis also tends to keep someone rooted in a neighborhood: the local café, the corner shop and the people met on daily errands carry more weight than they would for most.
When planets sit here, communication becomes central to life. Mercury in the 3rd is at home: a quick mind, constant curiosity, a knack for writing or teaching. The Moon here lets thinking follow feeling and often brings a habit of journaling or close, frequent contact with siblings. Saturn in the 3rd can mean slow early learning or a sense of not being heard, which over time turns into rigor and words that carry weight. Uranus here gives original ideas and a mind that jumps between subjects.
An empty 3rd house does not mean you have no siblings or struggle to communicate. Read the sign on the cusp (Scorpio on the 3rd: you speak little and on purpose) and where its ruler sits.
Example: Mars in the 3rd tends to argue fluently and sometimes sharply, drive fast, and have either a rivalry or an intense alliance with a sibling. Well channeled, it makes someone who defends ideas with energy and shines in debate or journalism.
4th house: home, family and roots
The 4th house begins at the IC, the lowest point of the chart, and represents what lies underneath everything: home, family of origin, roots, private life, the relationship with one parent, and how the last stage of life is lived. Its natural sign is Cancer and its ruler the Moon. It is angular, so what happens here has visible consequences even though it happens behind closed doors.
Tradition argues over which parent belongs to the 4th and which to the 10th; in practice, read it as the parent who most shaped the atmosphere at home. Planets here describe that atmosphere. The Moon in the 4th gives deep attachment to home and family. Saturn here suggests early responsibilities or a cool family climate, and often an adult who builds a home of their own with great care. Uranus in the 4th points to moves, an unconventional home or a family with an unexpected twist. Pluto here suggests intense family dynamics, secrets, or a deep transformation tied to where you come from.
An empty 4th house still has the IC as its cusp. Its sign and ruler describe your relationship with your roots: Libra on the IC wants a harmonious, good-looking home; Capricorn, a solid and orderly one.
Example: the Sun in the 4th means you were born at night, around midnight, and often describes someone who finds their center in private life: the home, their own family, or a project that grows out of public view before it becomes known.
5th house: creativity, romance and children
The 5th house is about pleasure and self-expression: creativity, play, romance (falling in love, as opposed to commitment, which belongs to the 7th), children, hobbies, sport for fun and speculation. Its natural sign is Leo and its ruler the Sun. It is succedent: what you produce out of your identity, whether a work or a child. In a practical sense, the 5th is where you go when nothing is required of you: what you choose to do with a free Saturday says a lot about it.
Planets here show how you have fun, how you fall in love and what you make. Venus in the 5th is one of the most romantic placements in a chart: artistic talent, a taste for courtship, an easy capacity for enjoyment. The Sun here, in its natural house, needs to shine through something of its own: a stage, a body of work, a project. Saturn in the 5th may take fun seriously or take time to allow itself to play; it is also linked with having children later or experiencing parenting as a weighty responsibility. Jupiter here expands creativity, appetite for risk and, traditionally, the bond with children.
An empty 5th house does not mean no children or no fun. Those questions are answered by the cusp sign, its ruler and the rest of the chart, never by the absence of planets.
Example: Mars in the 5th tends to experience love as a conquest and sport as a competition. It fits people who like to take risks, whether on a bet, on a stage or on a declaration of love with no safety net.
6th house: daily work, health and routines
The 6th house covers practical daily life: the work you do every day (not your career, which is the 10th), routines, health habits, service, coworkers and employees, and pets. Its natural sign is Virgo and its ruler Mercury. It is cadent: a house of adjustment, improvement and craft. The difference between the 6th and the 10th is worth holding onto: the 10th is the title on your business card, the 6th is what your Tuesday actually looks like.
Planets here describe your relationship with work and with your body as a tool. Mars in the 6th works hard and fast and needs to watch for burnout and inflammation; regular exercise helps it run well. Saturn here gives notable work discipline and sometimes a feeling that the work is never finished. Neptune in the 6th can point to a calling in care or service, but also to blurry routines and a physical sensitivity worth paying attention to. Venus here wants a pleasant workplace and usually gets on well with colleagues.
An empty 6th house says nothing good or bad about your health. Health is read from the whole chart and, above all, checked with a doctor: astrology diagnoses nothing. What the cusp sign and its ruler describe is your style with habits: Aries on the 6th works in bursts; Taurus, at a steady pace.
Example: the Moon in the 6th ties mood to routine. When the routine falls apart, so does the mood, and looking after others, people or animals, is often part of what keeps this person steady.
7th house: partnership, marriage and other people
The 7th house is the house of partnership and every one-to-one relationship: marriage, long-term partners, business partners, contracts, agreements and open opponents. It begins at the descendant, the point exactly opposite the ascendant, so it describes what you are not: what you look for, and often project, in someone else. Its natural sign is Libra and its ruler Venus. It is angular, so relationships here have visible, decisive effects.
The sign on your descendant is always the opposite of your rising sign. An Aries rising, independent and impulsive, has a Libra descendant and looks for a partner who brings tact and balance. A Virgo rising has a Pisces descendant and is drawn to the sensitivity and imagination it does not always allow itself.
Planets in the 7th describe the kind of bond and the kind of person who shows up. Venus here favors relationships and makes agreement easy. Saturn in the 7th tends toward serious commitments, sometimes late or with older partners, and bonds that strengthen with time. Mars here attracts direct, energetic people and can bring friction or competition into the partnership. Pluto in the 7th points to intense, transforming relationships, with power issues best faced head on. Uranus here needs freedom inside a relationship and is linked with unconventional arrangements or sudden beginnings.
An empty 7th house does not mean you will stay single. It is one of the most common worries and has no basis: every chart has at least two empty houses. Read the descendant sign and its ruler instead. Example: with a Cancer descendant, the Moon rules your 7th; if the Moon sits in your 10th, important relationships tend to cross paths with your working life, and meeting a partner through work is not unusual.
8th house: shared resources, intimacy and crisis
The 8th house is the house of what is shared and what is transformed: other people’s money and joint money (a partner’s income, inheritance, loans, debt, taxes, insurance), sexual and emotional intimacy, crisis, grief, and the capacity to come back after a loss. Its natural sign is Scorpio; its modern ruler is Pluto and its traditional ruler Mars. It is succedent and sits opposite the 2nd: what is yours against what is ours.
It has a reputation as the house of death, and in Hellenistic astrology it was one. To be plain about it: no planet in the 8th predicts how or when you will die, and there is nothing to fear from having planets here. What the house describes most usefully is how you handle trust, merging with another person, and change you did not choose.
Planets here deepen those experiences. The Sun in the 8th forges identity through crisis and often brings an interest in psychology, research or the hidden side of things. The Moon here feels deeply and finds it hard to show vulnerability. Venus in the 8th wants intense intimacy and is often associated with gains through a partner or associates. Jupiter here is traditionally linked with inheritance, financial support from others, or a talent for managing other people’s money. Saturn in the 8th calls for caution with debt and joint contracts and often shows difficulty letting go of control in intimacy, something that eases with age.
An empty 8th house is completely ordinary and does not mean a life without crisis or without a sex life. Read its cusp and ruler. Example: Mars in the 8th tends to meet crises head on, with strong desire and a relationship to shared money that needs clear agreements to avoid power struggles. Tradition associates it with surgery, investigative work and crisis management.
9th house: higher learning, travel and belief
The 9th house is the house of the wide horizon: higher education, philosophy, religion and belief, long journeys and foreign places, law, publishing and teaching. Its natural sign is Sagittarius and its ruler Jupiter. It is cadent and opposite the 3rd: the nearby mind against the mind looking for meaning. The 9th also covers the people who teach you and the ideas you would defend in public, so planets here often show up as a mentor figure or a lifelong subject.
Planets here describe how you search for meaning and relate to what is far away. Jupiter in the 9th, in its natural house, gives optimism, a love of learning and travel, and often a life that crosses into other cultures. The Sun here builds identity around a worldview, a faith or an academic discipline; it also means you were born in the early afternoon. Saturn in the 9th takes beliefs very seriously, questions and studies in depth, and may be slow to travel or to finish a degree. Mercury here gives a teacher’s or writer’s mind, an interest in languages and a gift for explaining complex ideas.
An empty 9th house does not mean you will never travel or study. Read the cusp sign (Gemini on the 9th: curious about many philosophies at once; Capricorn: practical beliefs and goal-driven study) and where its ruler sits.
Example: the Moon in the 9th tends to feel at home far from home. Tradition links it with people who emigrate, who are moved by languages, or who need a faith, a philosophy or a cause to feel at peace.
10th house: career, vocation and reputation
The 10th house is your public life: career, vocation, reputation, achievement, your relationship with authority and the place you hold in society. In Placidus it begins at the midheaven, the highest point of the chart at the moment of birth, which is why it describes what others see of you most clearly. Its natural sign is Capricorn and its ruler Saturn. It is angular, and tradition also links it with one parent, usually the one who stood for authority or the outside world.
The sign on the midheaven is one of the best clues to vocation. An Aries MC wants to lead and open new ground; Virgo, to perfect a craft; Pisces, to work with imagination or care; Aquarius, to innovate or work for a collective.
Planets in the 10th tend to be the most visible in the chart. The Sun here, near noon at your birth, gives ambition and a need for public recognition. The Moon in the 10th carries emotional life into the public sphere and is linked with careers that involve people or change over a lifetime. Saturn here, in its natural house, gives a slow, solid rise, early responsibility and authority earned through work. Jupiter in the 10th favors reputation and professional opportunity. Neptune here can bring an artistic or spiritual calling, and also a blurry or idealized public image that is worth defining.
An empty 10th house does not mean no career: the midheaven and its ruler are still there and are usually enough to read vocation. Example: with a Leo MC, the Sun rules the 10th; if your Sun sits in the 6th, career tends to be built through daily craft, service and doing one specific job extremely well, rather than through a sudden burst of fame.
11th house: friends, groups and hopes for the future
The 11th house is life in a network: friends, groups, associations, communities, collective causes, the contacts who help you and your plans for the future. Tradition called it the house of the “good spirit” and tied it to the rewards that come from career. Its natural sign is Aquarius; its modern ruler is Uranus and its traditional ruler Saturn. It is succedent and opposite the 5th: personal pleasure against shared goals.
Planets here describe how you relate to groups and what you hope for. The Sun in the 11th shines as part of a team and often has a wide circle or a visible role in a group. Venus here makes for affectionate friendships and sometimes love that grows out of friendship. Saturn in the 11th has few friends but long-lasting ones and may feel out of place in large groups. Uranus here, in its natural house, seeks like-minded communities, progressive causes or unconventional networks. Jupiter in the 11th is linked with help from contacts and with big goals.
An empty 11th house does not mean you have no friends. Read the cusp sign and its ruler: Cancer on the 11th turns friends into a second family; Scorpio makes for few friendships, deep and loyal.
Example: Mars in the 11th tends to drive or lead groups, causes and collective projects, and can clash with friends over how things should be done. It fits activists, organizers and people who get a project off the ground with a team.
12th house: the unconscious, retreat and what is hidden
The 12th house is the house of what is not seen: the unconscious, retreat, solitude chosen or imposed, spirituality, dreams, work done behind the scenes, and closed institutions such as hospitals, monasteries and prisons. Tradition called it the house of hidden enemies and self-undoing. Its natural sign is Pisces; its modern ruler is Neptune and its traditional ruler Jupiter. It is cadent and comes just before the ascendant: what is about to be born.
Planets here work quietly. A 12th-house planet within a few degrees of the ascendant was about to rise and is usually read strongly in the 1st as well. The Sun in the 12th means you were born within about two hours after sunrise; it describes someone who needs time alone to recharge and often works best without an audience. The Moon here hides feelings, even from itself, and easily tunes in to other people’s pain. Saturn in the 12th can bring vague fears that dissolve once they are looked at directly. Jupiter here is traditionally a “guardian angel”: help that arrives without fuss.
An empty 12th house does not mean a thin inner life. Read its cusp and ruler: Leo on the 12th may hide a pride that never shows; Virgo, a habit of worrying in silence.
Example: Neptune in the 12th, in its natural house, gives a fine sensitivity to art and spirit, vivid dreams and a need for retreat. Tradition associates it with musicians, therapists and people who work in hospitals or relief organizations.
How to find the ruler of a house
A house ruler is the planet that rules the sign on that house’s cusp. Finding it takes three steps: see which sign the cusp falls in, look up which planet rules that sign, then find which house and sign that planet occupies in your chart. That planet carries the affairs of the house into the area where it sits.
The rulerships are: Aries, Mars; Taurus, Venus; Gemini, Mercury; Cancer, the Moon; Leo, the Sun; Virgo, Mercury; Libra, Venus; Scorpio, Pluto (traditionally Mars); Sagittarius, Jupiter; Capricorn, Saturn; Aquarius, Uranus (traditionally Saturn); Pisces, Neptune (traditionally Jupiter). When Scorpio, Aquarius or Pisces is on a cusp there are two candidate rulers, and both are worth a look. The calculator above gives you the ruler of each of your houses.
A worked example. Say your 10th house cusp is at 14° Gemini. Step 1: the sign is Gemini. Step 2: Gemini is ruled by Mercury, so Mercury rules your 10th house, the house of career. Step 3: you look for Mercury in your chart and find it in Virgo in the 3rd house.
The reading almost writes itself. Career (10th) plays out through the 3rd: communication, writing, teaching, short trips, the local world. Mercury is also in Virgo, one of its two home signs, which sharpens precision and craft: this chart describes an editor, a translator, a teacher or anyone who makes a living explaining things exactly. If that Mercury also squares Saturn, as covered on our aspects page, the career path tends to be slower and more demanding, and also more solid.
You can go further. A planet that rules one house and sits in another links the two, and chains of rulers (your 10th-house ruler sits in the 3rd, the 3rd-house ruler sits in the 7th, and so on) map how the areas of your life connect. The ruler of the ascendant, called the chart ruler, matters most of all: its house shows where your basic energy is pointed.
Empty houses and intercepted signs
An empty house is simply a house with no planets in it, and every chart has them: with ten planets and twelve houses, at least two houses must be empty, and in practice it is usually five or six, because planets bunch together. Mercury never gets more than 27.8° from the Sun and Venus never more than 47.3°, as we calculated ourselves with NASA’s DE440 ephemeris for 1900–2100, so those three bodies often share one or two houses.
Empty does not mean unimportant. It means that area of life is not where your chart concentrates its tension or energy, but it is still active through the sign on its cusp and its ruler. An empty 7th house does not sentence you to being single, any more than an empty 2nd sentences you to poverty. And over the years, transiting planets will pass through every one of your houses and switch them on in their turn.
What a crowded house does show is the reverse: emphasis. Three or four planets in the same house (a stellium) tend to make that area a big part of the life story.
Intercepted signs are the other thing that confuses people. In unequal house systems such as Placidus, a house can be wider than 30°, and then it can contain a whole sign with no cusp falling in it. That sign is “intercepted.” Because opposite houses are the same size, the opposite sign is intercepted too. To balance it out, some other sign will appear on two consecutive cusps. If your 1st and 2nd house cusps are both in Gemini (at different degrees), there is very likely an intercepted sign elsewhere.
Interceptions become more common the farther from the equator you were born, because houses get more unequal there (see the next section). In Quito they are rare; in Madrid, New York or Buenos Aires they are common; in Reykjavík they are almost unavoidable. Many astrologers read planets in an intercepted sign as resources that take longer to come out; others give interceptions no special meaning. Equal and whole sign houses never have them.
House systems: Placidus, Koch, Equal, Whole Sign and others
A house system is the method used to divide the sky into twelve parts, and there are several because there is no single natural way to do it: you can divide time, space or the zodiac. Nearly all of them agree on the ascendant and midheaven; they differ on the in-between cusps (2, 3, 5, 6, 8, 9, 11 and 12), which is why a planet can change house when you switch systems.
Placidus is the most widely used system in modern Western astrology and the one cartanatal.app uses. It divides time, not space. Every degree of the zodiac takes a certain time to climb from the horizon to the meridian (its diurnal semi-arc) and to travel below the horizon to the lowest point (its nocturnal semi-arc). Placidus splits those semi-arcs into three equal slices of time: the 12th house cusp is the degree that has covered one third of its journey from the ascendant up to the midheaven; the 11th, two thirds. The 2nd and 3rd come from the nocturnal semi-arc the same way, and the rest are their opposites.
Koch, also called the birthplace system, is similar in spirit but is built on the time the midheaven degree takes to rise. It gives results close to Placidus at mid latitudes and is popular in German-speaking countries. Regiomontanus divides the celestial equator into equal parts and projects them onto the ecliptic; it dominated European astrology for centuries and is still used in horary work. Campanus divides the prime vertical, the circle through east, zenith and west. Porphyry splits each quadrant, the arc between two angles, into three equal stretches of zodiac; it is simple and works at any latitude.
Equal houses draws twelve houses of exactly 30° from the ascendant. It is simple and has no interceptions, but the midheaven stops being the 10th house cusp and can fall in the 9th or the 11th. Whole sign houses is the oldest: the whole rising sign is the 1st house, the next sign the 2nd, and so on. It was standard in Hellenistic astrology and has made a strong comeback.
Why don’t they agree? Because each answers a different question about what “a twelfth of the sky” means. None of them is objectively right. We use Placidus because it is the standard of modern psychological astrology, most books and astrologers use it, and it respects both axes of the chart: the ascendant opens the 1st house and the midheaven opens the 10th. If you compare your chart with another site and a planet lands in a different house, check the house system first and the birth time second.
Why house sizes depend on latitude
Placidus houses are almost never 30° wide, and how unequal they get depends mainly on the latitude where you were born: near the equator the twelve houses are close to equal, while toward the poles some shrink and others stretch across several signs. We computed, for each city, the smallest and largest house that appears over a full sidereal day:
| City | Latitude | Smallest house | Largest house |
|---|---|---|---|
| Quito | 0.2° S | 27.6° | 32.6° |
| Bogotá | 4.6° N | 27.0° | 33.5° |
| Mexico City | 19.4° N | 24.5° | 37.5° |
| Buenos Aires | 34.6° S | 21.2° | 44.0° |
| Madrid | 40.4° N | 19.6° | 47.8° |
| New York | 40.7° N | 19.5° | 48.1° |
| London | 51.5° N | 15.7° | 60.5° |
| Moscow | 55.8° N | 13.6° | 69.8° |
| Reykjavík | 64.1° N | 6.8° | 114.9° |
The reason is that Placidus divides time, not degrees. A third of a degree’s semi-arc is a stretch of time; how many zodiac degrees fit into that stretch depends on how fast that part of the ecliptic is rising. And the ecliptic, tilted 23.44° to the equator, does not rise at a steady rate: as we show on the rising sign page, in Moscow Libra takes three hours to rise and Aries forty-two minutes. The same slice of time holds few degrees of a slow sign and many of a fast one.
At the equator every degree spends exactly twelve hours above the horizon, so every semi-arc is six hours. Even so, Quito’s houses are not equal, because the tilt of the ecliptic makes some degrees cross the meridian faster than others; that is the minimum spread, 27.6° to 32.6°. Moving away from the equator adds a second effect: degrees whose declination is on your side of the equator stay above the horizon far longer than those on the other side, so semi-arcs become very unequal. In New York or Madrid one house can be under 20° and another nearly 48°; in Reykjavík a single house can span almost four signs.
Above the Arctic Circle (66.6°), in Tromsø at 69.6° N for example, the problem stops being one of size: at certain moments parts of the ecliptic neither rise nor set, and a degree that never touches the horizon has no semi-arc to divide. For some birth times Placidus has no solution at all, and software falls back on another system, usually Porphyry or whole sign. If you were born in northern Norway, Sweden, Finland, Alaska or Siberia, it is worth knowing which system your houses were calculated in.
For most readers the practical upshot is this: a chart cast for Singapore or Bogotá has nearly equal houses, while one cast for London, Seattle or Melbourne regularly has intercepted signs. That is not a calculation error; it is the geometry of the sky at your latitude.
Frequently asked questions
What are the houses in astrology?
They are the twelve divisions of a birth chart, drawn from the horizon and meridian at your place and time of birth. Each one represents an area of life, such as money (2nd house), partnership (7th) or career (10th).
How do I calculate my astrology houses?
You need your date, exact time and place of birth. With those, the calculator on this page gives you every house cusp, the planets in each house and each house’s ruler, using Placidus houses.
What does an empty house mean in astrology?
It means no planets fall in that area of life, not that it doesn’t matter. Every chart has at least two empty houses; they are read through the sign on the cusp and the position of its ruler.
Which house is marriage and love?
The 7th house rules committed partnership, marriage and business partners; the 5th rules romance and falling in love. The 8th adds intimacy and what a couple shares.
Which house rules money?
The 2nd house rules your own money, what you earn and own. The 8th rules shared money and other people’s: inheritance, debt, a partner’s finances. The 10th and 6th describe the career and daily work that produce it.
Which house system is the most accurate?
None is objectively correct. Placidus is the most used in modern astrology and the one we use; whole sign houses is the oldest. What matters is knowing which one was used when you compare charts.
Can I know my houses without a birth time?
Not reliably. House cusps move about 1° every 4 minutes, so an hour’s error shifts the houses by half a sign. Without a time you can read planets by sign and aspect, but not by house.
What if a planet sits right on a house cusp?
It is read as acting in both houses, and many astrologers treat a planet within about 2° to 3° before a cusp as already belonging to the next house. In those cases the accuracy of the birth time is decisive.