Compatibility in synastry depends upon a combination of factors in the subjects’ birth charts.  But with so much information available to the budding astrologer, the process can seem hopelessly complex. Where do you start?  What do you look for?  Here’s a sampling of compatibility issues to ask yourself about when reading the charts, and possible contributing factors.   I base this on various astrology books.

Guidelines

Before you use this list, please note:  This is only a partial and general guide!  Don’t take everything as if it were written in stone.  Interpretation in astrology isn’t like that.  Instead, use this as an aid and allow yourself to learn through observation.  In time, you can build your own list.

This page will be updated often.

Compatibility Checklist

What is each partner like alone?

  • Sun, moon, ascendant signs
  • Emphasized houses
  • Stelliums (several planets in same sign)
  • Dignified (strong) planets

Are their forms of expression and ways of relating similar?

  • Ascendant signs and aspects
  • Mercury and Venus signs
  • Aspects between Mercurys, Venuses and/or Mercury and Venus
  • Planets in the first house in each chart

What does each partner want in a relationship?

  • Ruler of seventh house (marriage)
  • Planets in seventh house
  • Ruler of fifth house (sex and children)
  • Planets in fifth house
  • Ruler of fourth house (home)
  • Planets in fourth house

Do their personalities complement each other?

  • Ascendant, sun and moon signs compatibility
  • Aspects between sun and moon

Can they communicate well with each other?

  • Compatible Mercury signs
  • Aspects from Mercury to the sun, moon and/or Mercury

Is there emotional sympathy between them?

  • Aspects between moon and Venus, moon and moon and/or Venus and Venus

Do they feel at home with each other?

  • Personal planets in fourth house overlay
  • Aspects between moons

Are there signs of long-term commitment?

  • Sun and/or Moon in angular house overlays
  • Aspects between Saturn and Sun and/or Saturn
  • Sun, moon and/or Venus in seventh house overlay
  • Planets in natal seventh house (shows attitude toward marriage and signifies partner)
  • Conditions of moon and Venus in natal charts (ability of each person to love and be intimate)

Is there sexual or romantic attraction?

  • Aspects from Venus to Mars, ascendant, Uranus or Neptune
  • Aspects between sun and moon (general attraction)
  • Aspects between ascendants (first house cusp)

Are they sexually compatible?

  • Aspects between Venus and Mars
  • Planets in fifth house overlays
  • Planets in natal fifth house (shows attitude toward sex)

How does each partner impact the other’s life?

  • Planets overlaying empty houses (puts spotlight on those areas)
  • Planets overlaying full houses (challenges or supports one’s view of that house)
  • Planets overlaying angular houses (strong influence)

Are there signs of lack of sympathy?

  • Negative aspects from Saturn to moon and/or Venus
  • Incompatible sun, moon and/or ascendant signs
  • Incompatible Venus signs
  • Lack of Mercury aspects

Will the partners transform each other’s lives?

  • Aspects from Uranus, Neptune and/or Pluto to the sun, moon, ascendant or other important planet
  • Uranus, Neptune and/or Pluto in angular house overlay
  • Uranus, Neptune and/or Pluto overlaying an emphasized house

What were the influences when they met?

  • Negative Uranus transits to Venus (may be a sign the relationship is unstable)
  • Saturn transits (can make relationship burdensome)
  • Jupiter transits (good feelings, not necessarily lasting)

Do they have the same goals and ambitions?

  • Compatible sun signs
  • Aspects between sun and Mars, Jupiter and/or Saturn
  • Sun in tenth or eleventh house overlay

Want to Learn More About Synastry?

That’s just to name a few possible factors in horoscope compatibility.  Don’t miss the guide on how to do synastry, house overlays and the free synastry aspects guide.  Or if you want to go to the same sources that this guide is based on, please check out the books on astrology post.