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The 7th house is the part of a birth chart that describes committed one-to-one relationships: marriage, long-term partnership, close business partners and even open adversaries. Its starting point, the descendant, is the degree of the zodiac that was setting on the western horizon at the exact moment and place you were born.
That is why a 7th house calculator needs more than a birth date: the descendant changes sign roughly every two hours, so two people born on the same afternoon in the same city can have entirely different 7th houses.
What the 7th house and the descendant are
Every birth chart is built on two axes. The horizontal one runs from the ascendant (the eastern horizon, the 1st house cusp) to the descendant (the western horizon, the 7th house cusp). The two points are always exactly opposite: if your ascendant is 8° Leo, your descendant is 8° Aquarius. The ascendant describes how you meet the world on your own; the descendant describes what you look for, and often what you project, in the people you bind yourself to.
Traditionally the 7th house covers the spouse or partner, but also contracts, negotiations and rivals you deal with face to face: anyone who stands across the table from you as an equal. Modern readings focus on love and commitment, as the calculator's text does. The house has three layers:
- The descendant sign and degree, which sets the tone of the house.
- The 7th house ruler, the planet that rules the descendant sign, and where it sits in the chart.
- Planets inside the 7th house, if there are any, which add their own themes to partnership.
How the 7th house is calculated
The calculation starts with your birth date, exact birth time and birth place. The time is read as a wall-clock time in the birth place's own IANA time zone, with the historical daylight-saving rules that applied on that date. A birth recorded as 9:00 in summer time is a different instant from 9:00 standard time, and many countries have changed their clock rules over the last century.
Planetary positions come from the NASA JPL DE440 ephemeris, and house cusps are computed with the Placidus system in the tropical zodiac. Near the polar circles, where Placidus cusps can fail to form, the chart falls back to Porphyry, which divides each quadrant evenly. In both systems the 7th house cusp is the descendant itself.
Why the exact time matters
The ascendant and descendant travel through all twelve signs in about a day, on average around 1° every four minutes, though the speed varies with latitude and with the sign on the horizon. A birth time off by 15 minutes can shift the descendant by three or four degrees: enough to change the sign near a cusp, or to move a planet into or out of the 7th house.
If you are unsure of your rising sign, run the ascendant calculator first; your descendant is always the sign directly opposite.
How to read your 7th house results
Descendant sign and degree
This is the headline result. The sign describes the qualities you are drawn to and the kind of relationship that feels balanced to you. The degree tells you how far into the sign the cusp falls; a descendant at 28° or 29° sits close to the next sign, which is a cue to double-check your birth time.
Relationship style, ideal partner qualities and challenges
These three sections expand the descendant sign: how you approach commitment, which traits feel attractive and complementary, and the friction the sign tends to bring, often where a quality you admire in a partner turns into one that frustrates you.
Partner portrait
The partner portrait is a short composite sketch built from the descendant sign. Read it as a description of a role a partner tends to play in your life, not as a physical or biographical description of a specific person.
The 7th house ruler
The ruler is the planet that governs your descendant sign. This calculator uses the traditional rulerships only, so Scorpio is ruled by Mars, Aquarius by Saturn and Pisces by Jupiter, rather than Pluto, Uranus or Neptune. You will see the ruler's sign, degree, the house it occupies and whether it was retrograde at birth.
The ruler's house often points to where partnerships begin or what they revolve around. In the 10th it links partnership with career and public life; in the 9th, with travel, study or a partner from a different background; in the 6th, with work and daily routines. A retrograde ruler is read as a more inward or delayed expression of partnership themes, not as a bad sign.
| Descendant | Rising sign | Traditional ruler | Partnership theme |
|---|---|---|---|
| Aries | Libra | Mars | Directness, energy, a partner who takes the lead |
| Taurus | Scorpio | Venus | Steadiness, loyalty, physical comfort |
| Gemini | Sagittarius | Mercury | Conversation, curiosity, variety |
| Cancer | Capricorn | Moon | Emotional care, home, protection |
| Leo | Aquarius | Sun | Warmth, generosity, visible devotion |
| Virgo | Pisces | Mercury | Practical help, attention to detail |
| Libra | Aries | Venus | Fairness, harmony, cooperation |
| Scorpio | Taurus | Mars | Intensity, depth, emotional honesty |
| Sagittarius | Gemini | Jupiter | Freedom, shared beliefs, adventure |
| Capricorn | Cancer | Saturn | Commitment, structure, long-term goals |
| Aquarius | Leo | Saturn | Friendship, independence, unconventional terms |
| Pisces | Virgo | Jupiter | Compassion, idealism, spiritual connection |
Planets in the 7th house
Planets between the descendant and the 8th house cusp are listed with short interpretations. Venus here emphasizes affection and harmony; Saturn, seriousness and responsibility; Mars, passion and some friction; the Moon, emotional need and care. An empty 7th house is common and does not mean relationships are unimportant; the descendant sign and its ruler carry the story.
Reading your 7th house step by step
- Note the descendant sign and degree, and check whether it is within a degree or two of a sign boundary.
- Read the relationship style, ideal partner qualities and challenges as one description of the same sign.
- Find the 7th house ruler and its house; ask what that area of life has to do with your partnerships.
- Check the ruler's sign and retrograde status for how comfortably it can act.
- Add any planets in the 7th house, which tend to be the loudest voices in this area.
- Compare the result with your ascendant: what you show the world and what you seek in others usually form a balancing pair.
A worked example
Take a hypothetical chart with the descendant at 14° Capricorn, so the ascendant is 14° Cancer. The Capricorn descendant suggests someone who values reliability and may be drawn to partners who seem mature or established. The challenge is relationships that feel like duty, or choosing stability over warmth.
The ruler is Saturn. Suppose it sits retrograde in Aries in the 10th house. That ties partnership to career and reputation, such as partners met through work. Saturn is traditionally weak in Aries, and the retrograde adds a slower, reflective quality, so commitments may come after careful thought or later in life.
Finally, suppose Venus is in the 7th house. That softens the Capricorn tone, adding affection and a wish for harmony. The picture is a person who wants both security and tenderness.
For the full picture, including aspects to the 7th ruler, open your free birth chart report.
Common mistakes when reading the 7th house
- Using an approximate birth time. "Around noon" can mean a different descendant sign. Use a recorded time when you can.
- Ignoring the time zone and daylight saving. Entering a summer-time birth as if it were standard time shifts the chart by an hour, roughly 15° on the horizon.
- Mixing rulership systems. Reading Pluto as a Scorpio descendant's ruler in one place and Mars in another muddles the interpretation. This calculator uses traditional rulers throughout.
- Treating an empty 7th house as a warning. Many charts have no planets there.
- Reading the descendant as a Sun sign match. A Taurus descendant does not mean a Taurus partner. It describes qualities, which can show up through any sign.
- Stopping at the descendant. The ruler and any planets in the house often say more than the sign alone.
If you want another angle on partnership, the Juno asteroid calculator looks at the asteroid traditionally linked with commitment, and the love compatibility calculator compares two signs directly.
Accuracy and limits
Given a correct birth time, date and place, the descendant is computed to a fraction of a degree. The weak point is the input. Recorded birth times are often rounded to five or fifteen minutes, and family memories can be off by more. If your descendant falls near a sign boundary, or a planet sits close to the 7th or 8th house cusp, treat that detail as uncertain and read both possibilities. Older births can also carry time zone uncertainty, because historical clock rules were not always applied consistently.
Above all, the 7th house is symbolic. It describes patterns and needs in how you relate to others. It does not predict a specific person, a wedding date or whether a relationship will last, and it is no substitute for your own judgment.