The Absolute Best Synastry Aspects

The Synastry Chart, in addition to the Composite Chart, provides much insight into overall compatibility of a couple. The Composite Chart represents the relationship itself and what the two of you create when you are together. Synastry, on the other hand, explains how two people affect and influence each other directly. Both are very important to consider in a relationship.

So, what are the absolute best synastry aspects?

Well-Aspected 7th House Rulers 

What is your 7th house ruler?

  • If your 1st house is in Aries, your 7th house ruler is Venus
  • If your 1st house is in Taurus, your 7th house ruler is Pluto
  • If your 1st house is in Gemini, your 7th house ruler is Jupiter
  • If your 1st house is in Cancer, your 7th house ruler is Saturn
  • If your 1st house is in Leo, your house ruler is Uranus
  • If your 1st house is in Virgo, your house ruler is Neptune
  • If your 1st house is in Libra, your house ruler is Mars
  • If your 1st house is in Scorpio, your house ruler is Venus
  • If your 1st house is in Sagittarius, your 7th house ruler is Mercury
  • If your 1st house is in Capricorn, your 7th house ruler is your Moon
  • If your 1st house is in Aquarius, your 7th house ruler is your Sun
  • If your 1st house is in Pisces, your 7th house ruler is Mercury

I’ve said it before, and I’ll say it again: the 7th house ruler for each partner is very important in synastry. The 7th house represents commitment and partnership, so you can tell a lot about a relationship when looking at how each person’s 7th house ruler is aspected.

If your 7th house ruler receives a square from your partner’s Saturn, it may be difficult to get the relationships off the ground. There may be obstacles and barriers to you being together.

If your Uranus is square your partner’s 7th house ruler, you bring an unstable and unpredictable energy to your partner’s area of partnership and commitment. Your partner likely sees you as someone undependable and erratic, and it may be difficult for you to make a full commitment to each other.

Sun conjunct Moon (trine, opposition, and sextile also work)

The Sun represents ones essence and personality, while the Moon represents our emotions and what makes us feel secure. Postiive aspects between the Sun and Moon in synastry indicate a ‘marriage’ between the yin and yang. The Sun person feels supported and cared for by the Moon person, and the Moon person feels safe and loved by the Sun person. Together, they make a great team. The opposition is also potent in synastry because it indicates a lot of fascination and attraction between the couple. As they say, “opposites attract”!

Sun conjunct Venus (trine, opposition, and sextile also work)

Venus represents love and beauty, while the Sun represents one’s essence and true self. Aspects between these two planets indicate love, pure and simple. This is not a wildly obsessive, romantic type of love, as it is commonly seen in the charts of good friends and family members. In a romantic relationship, however, this aspect is wonderful, for it increases the compatibility between you, and signifies that you really ‘like’ each other!

heaven sky astrology multicolor universe
Image by on Freepik
Moon conjunct Venus (trine, opposition, and sextile also work)

I may be biased because I have had this aspect so many times (particularly the conjunction), but it is truly a magical connection to share with someone. This is such a sweet, caring and loving aspect. The two people feel very ‘at home’ with each other. Expressing your love and emotions to one another feels easier than usual. You bring out each other’s sweetness and vulnerability. This is such a perfect aspect to find in a synastry chart.

Venus conjunct Mars (trine, opposition, and sextile also work)

Interaspects between Venus and Mars are so spicy hot and deserve a spot in my list of best synastry aspects! These aspects indicate the blending of love with sex, leading to much passion and desire. I’ve found this aspect keeps the fire burning between a couple for a very long time, which is so important when it comes to keeping a relationship fresh. Sex is satisfying and usually quite frequent. The two of you intuitively know how to turn each other on, and can barely keep your hands off each other.

Moon or Venus in the same sign (i.e. Moon conjunct Moon, Venus conjunct Venus)

I’ve seen way too many of these aspects in synastry charts, so I had to mention them! The Moon represents our emotional nature, so when it is in conjunction to another person’s Moon, emotional compatibility is indicated.

The same can be said about Venus – these two express love in the same way, so it makes sense that they would be happy together. There is an intuitive understanding between them, and neither has to explain themselves too much. They just *get* each other.

Personal planets conjunct the North Node (especially Sun, Moon, Venus or ruler of the 7th house)

If your planet makes a conjunction to another person’s North Node, there is a feeling that the two of you are heading somewhere together. Both partners can feel progress taking place when they are with each other. It’s a bizarre feeling to explain: it may feel uncomfortable, but it also feels right.

The planet person is guiding the North Node person towards their potential and encouraging them to come out of their comfort zone. This aspect tends to bind people together for a long time, for the feeling of fate is very strong.

What about the South Node? This CAN bind people together for a very long time, and usually does. However, the South Node is very draining, especially for the planet person, so it might not work out in the long run. Check out my South Node article to find out more.

Conjunction to Vertex (especially inner planets)

So many long term couples have significant Vertex contacts in synastry, especially when they involve inner planets. For example, one person’s Sun conjunct another person’s Vertex.

The Vertex is seen as a point of fate, so someone who has strong Vertex aspects with you impacts you powerfully. It feels like this relationship is meant to be, and you can feel this when you are together.

Venus sextile or trine Pluto

I had to add Venus-Pluto to this list. It is the ultimate ‘Beauty and the Beast’ aspect, as it indicates the blending of love (Venus) and intense passion (Pluto).

Hard aspects can be hard to deal with, depending on your personality. Some people simply need drama and intensity in their relationships, so they can ‘handle’ hard Venus-Pluto aspects.

Softer aspects, however, are much easier to deal with. They inject a good amount of intensity and passion without being overwhelming. There is a deep love and intensity between the couple without the power struggles and intense jealousy that come with the hard aspects.

Mars sextile or trine Pluto

This aspect is another one of my favourites. The sexual connection in this case is off the charts!

Mars represents sex and energy, while Pluto represents intensity and passion. As you can imagine, the blending of these two planets indicates a lasting sexual connection.

In this relationship, sex is fulfilling and satisfying for both parties.

House overlays in “relationship” houses

These houses are: the 1st house, 4th house, 5th house, 7th house and 8th house.

The 1st house represents one’s physical appearance and persona. If someone’s planets fall in this house, there is a good indication of attraction, or at least taking notice of you. Venus and Mars in this house are especially sexy.

The 4th house represents one’s home, family, and past. Someone’s planets in your 4th house indicates they impact you on a deep level. The 4th house is a watery, emotional house, so this person may bring you in touch with deep emotions.

The 5th house represents fun, games, and romance, so planets overlaying in this house indicates a strong bond between the individuals. The house person feels more romantic and flirty around the planet person, and there the two of them feel very good when they are together.

The 7th house represents partnerships and formal commitments, so it is no surprise that this house is important when it comes to relationships. When someone’s planets fall in your 7th house, you cannot help but want to partner with them in some way. You naturally want to build an equal and harmonious bond with them, and want their input in your decisions. They force you to look at the other side of the coin and see a different perspective, almost like they are a mirror to you.

The 8th house represents sex, intimacy, and passion, so this house is an important one to consider in synastry. When someone’s planets fall in your 8th house, they bring up very intense feelings from you. You cannot feel indifferent to them; there is usually a love-hate theme in the relationship. You love them passionately, but despise them equally when you feel upset with them. Sex and intimacy are taken to another level in 8th house relationships; you truly feel you want to merge with each other.

Please note: you should look at the house overlays of both partners. If you find that one person’s planets overlay onto your ‘relationship houses’, while your planets do not overlays onto their ‘relationship houses’, an imbalanced relationship can be indicated.

For example, if my Sun falls in your 8th house, you feel very strongly for me. I bring out very deep and intense feelings out of you, and you feel I have a transformative effect on your life. If your Sun falls in my 11th house, I might not feel the same way. I might see you as more of a friend than a lover, which might be devastating for you.

This list is not exhaustive, and you do not need to have every single aspect in your synastry chart for the relationship to work. As I’ve said before, I think a good Composite Chart is more important than good Synastry (at least in terms of long-term compatibility), so there’s that.


Click here to read The Absolute Best Composite Aspects

Click here to return to the Relationships page


How to read a Synastry Chart

The Synastry chart is one of the most important tools to use when assessing compatibility between two people.

The two areas you want to focus on are: house overlays and planetary aspects. 

House overlays

What are houses? Our natal charts are divided up into 12 houses, which each represent a different area of our life:

Here is a breakdown of what each house represents

  • The first house: represents the self, one’s persona, and one’s physical appearance
  • The second house: represents finances, income, material possessions, and self-worth
  • The third house: represents communications, neighbourhood, siblings, learning, local travel
  • The fourth house represents: family, home, past, ancestry, real estate
  • The fifth house represents: children, creativity, romance, fun, leisure
  • The sixth house represents: work, health, coworkers. productivity
  • The seventh house represents: partnership (business and romantic), commitment, sharing, equality
  • The eighth house represents: intimacy, death, transformation, other people’s money, taxes
  • The ninth house represents: travel, higher learning, philosophy, religion
  • The tenth house represents: career, social status, public reputation
  • The eleventh house represents: friends, groups, long-term goals
  • The twelfth house represents: spirituality, solitude, dreams, illusions

What are planets? Our natal charts contain 10 planets. Each represents a different aspect of our personality.

Here is a simple breakdown of what each planet represents

  • Sun: Your basic personality, ego, individuality
  • Moon: your emotional nature and what makes you feel secure
  • Mercury: your communication style and intellectual interests
  • Venus: your love style, what you find beautiful, your personal style
  • Mars: your determination, passion, and sex drive
  • Jupiter: represents expansion, generosity and luck
  • Saturn: represents structure, maturity, commitment, restriction
  • Uranus: represents instability, freedom, unpredictability
  • Neptune: represents illusions, compassion, sensitivity
  • Pluto: represents transformation, obsession, jealousy, power

When comparing two charts, you can see where each person’s planets land in another person’s chart.

For this exercise, let’s look at Kim and Ye’s Synastry. I generated this report on

When assessing synastry, check to see where your personal planets fall in the other person’s chart:

  • When someone’s planet falls into one of your houses, they bring the energy of that planet into your house.
  • As you can see from their chart, Ye’s Sun/Jupiter conjunction resides in Kim’s 7th house of partnership and commitment– this is an excellent indication of compatibility and marriage. Ye’s Venus and Mars reside in Kim’s 5th house, which is a great indication of romance and having children.
  • Kim’s Sun resides in Ye’s 4th house of home and family. This is again a great indication of a long-lasting relationship

In a romantic relationship, focus on looking for overlays in the following houses:

  • The first house: another person’s planets falling in your 1st house indicate they are very attracted to you. This is especially powerful if the Sun, Moon, Venus or Mars are in another person’s 1st house, as they are deeply personal planets and increase attraction.
  • The fourth house: represents home, family, and emotions. When someone’s planets fall in your 4th house, they feel like family to you, and you enjoy spending time together at home. This is an indication of wanting to build a home and family together.
  • The fifth house: represents romance, children, and fun, so someone’s planets falling in this house is a great aspect.
  • The seventh house: represents commitment, partnership, equality, etc., so it is obviously a very important house to consider in a synastry chart. If someone’s planets fall in your 7th house, you feel compelled to partner with them. They teach you about compromise, relating, and partnership.
  • The eighth house: represents deep intimacy and bonding, so overlays to this house are very powerful and transformative. These types of relationships are not for the faint of heart, but are ultra intense and sexy (if you like that kind of thing).

Check out my articles on house overlays to learn more:

Sun in the Houses in Synastry

Moon in the Houses in Synastry

Venus in the Houses in Synastry

Mars in the Houses in Synastry

Jupiter in the Houses in Synastry

Saturn in the Houses in Synastry

Uranus in the Houses in Synastry

Neptune in the Houses in Synastry

Pluto in the Houses in Synastry


Planetary Aspects

After looking at house overlays, it is equally important to look at the aspects each person’s planets make the other persons’ planets.

To make things easy, you can generate reports in by clicking PDF Additional Tables after generating a report.


Reports like these make is easier to assess your planetary overlays with someone:

In this table, you might not recognize the symbols and numbers.

The symbols within the table show the aspect each planet is making to the other. For example, Ye’s Sun is square Kim’s Venus. Check out this article to learn what the symbols represent. The ones you want to focus on most are: Conjunction, Square, Opposition, Trine, and Sextile.

  • Sextiles and trines are nice, harmonious aspects, and are great to see in a chart.
  • Conjunctions are very powerful, and show compatibility between the energies each planet represents.
  • Oppositions can be problematic, but are usually very fascinating. This is a case of ‘opposites attract’.
  • Squares are considered the most problematic, as they cause friction and lack of understanding between the parties.

If you are looking to assess romantic, long-term compatibility with someone, it is very important to look at how each person’s Love planets are aspected in a chart.

Generally, squares from Saturn, Uranus, Neptune, or Pluto are not looked upon very favourably, especially if they make an aspect to someone’s personal planets (Sun, Moon, Mercury, Venus, Mars).

Check out my synastry articles to read about specific aspects.


It is also extremely important to look at how someone’s planets aspect your 7th house ruler. What is your 7th house ruler?

  • If your 1st house is in Aries, the Composite 7th house ruler is Venus
  • If your 1st house is in Taurus, the Composite 7th house ruler is Pluto
  • If your 1st house is in Gemini, the Composite 7th house ruler is Jupiter
  • If your 1st house is in Cancer, the Composite 7th house ruler is Saturn
  • If your 1st house is in Leo, the Composite house ruler is Uranus
  • If your 1st house is in Virgo, the Composite house ruler is Neptune
  • If your 1st house is in Libra, the Composite house ruler is Mars
  • If your 1st house is in Scorpio, the Composite house ruler is Venus
  • If your 1st house is in Sagittarius, the Composite 7th house ruler is Mercury
  • If your 1st house is in Capricorn, the Composite 7th house ruler is the Moon
  • If your 1st house is in Aquarius, the Composite 7th house ruler is the Sun
  • If your 1st house is in Pisces, the Composite 7th house ruler is Mercury

In my opinion, this is the most important planet to look at when considering long-term compatibility.


All in all, synastry aspects and overlays are extremely important to consider in a synastry chart. However, I believe the Composite Chart is more essential to assess long-term compatibility. Click here to read my article on The Best Composite Chart Aspects.