Synastry Analysis
Cosmic Compatibility
Discover the astrological dynamics between two charts
Full synastry — inter-chart aspects with measured orbs, not Sun-sign matching
Comparing charts and finding aspects…
Same two charts → the same measured aspects, always
Astrological meaning is tradition, offered for reflection and entertainment — not advice, prediction, or scientific fact. The astronomy underneath is computed and checkable.
The harmony ring and these category bars are a traditional interpretive reading, offered for entertainment and reflection on the aspects below — not a measurement or score of your relationship.
Any keepsake or reading here is astrological tradition, offered for reflection and entertainment — not advice, prediction, or scientific fact. The astronomy underneath is computed and checkable.
The Composite Chart
The composite is the midpoint of positions: for each planet we take the point exactly halfway between where it sat in each person's chart. The result is a single derived chart that portrays the relationship as a blend of two natures.
It is a mathematical average, not a chart cast for any real moment — so it has no true rising sign or houses. For a relationship chart anchored to an actual instant in spacetime, see the Davison tab.
The Davison Relationship Chart
The Davison chart is a real chart cast for the relationship's midpoint in spacetime: the moment exactly halfway (in Universal Time) between the two birth moments, at the geographic midpoint between the two birthplaces.
Because it is an actual chart for an actual instant, it carries a genuine Ascendant, real houses, and the true planetary sky of that moment — which is what distinguishes it from the composite's averaging of positions.
Sign Compatibility by Element
In the astrological tradition, the four elements are read as interacting in the patterns below — offered for reflection and entertainment, not fact or prediction. Full synastry goes far deeper — use the calculator above for a fuller picture.
Fire Signs — Aries, Leo, Sagittarius
Fire signs thrive with fellow Fire (shared passion and drive) and Air signs (Air fans the flames). Water can extinguish Fire's enthusiasm, while Earth may feel too slow or restrictive. Key strengths: vitality, inspiration, spontaneous adventure.
Earth Signs — Taurus, Virgo, Capricorn
Earth signs blend beautifully with other Earth signs (shared values and groundedness) and Water signs (Water nourishes Earth's growth). Fire can feel restless, and Air may seem ungrounded. Key strengths: loyalty, stability, sensual depth.
Air Signs — Gemini, Libra, Aquarius
Air signs connect effortlessly with fellow Air (meeting of minds) and Fire signs (ideas ignite action). Earth may feel heavy or limiting, while Water can be emotionally overwhelming. Key strengths: intellect, wit, adaptability.
Water Signs — Cancer, Scorpio, Pisces
Water signs form profound bonds with fellow Water (deep emotional attunement) and Earth signs (Earth holds Water safely). Fire can evaporate Water's sensitivity, and Air may feel too detached. Key strengths: empathy, intuition, transformation.
Sun Sign Compatibility Grid
A quick elemental overview of Sun sign compatibility, read as an etched frost panel — the brighter the mark, the higher the natural harmony; the fainter, the more the full chart decides. In the astrological tradition this is a starting point for reflection and entertainment, not a verdict.
| Sign | Ari | Tau | Gem | Can | Leo | Vir | Lib | Sco | Sag | Cap | Aqu | Pis |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Ari | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Tau | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Gem | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Can | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Leo | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Vir | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Lib | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Sco | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Sag | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Cap | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Aqu | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
| Pis | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● | ● |
Based on elemental compatibility only. Every real relationship is far more nuanced — use the full synastry calculator above for an accurate reading.
How It Works
What Is Synastry?
Synastry is the branch of astrology that compares two birth charts to analyse the relational dynamics between two people. By overlaying Person A's chart onto Person B's, we reveal every cross-chart planetary aspect — Venus conjunct Mars, Sun trine Moon, Saturn square Mercury — each read in the astrological tradition as a signature of attraction, challenge, or harmony.
In the astrological tradition, harmonious aspects such as trines (120°) and sextiles (60°) are read as areas of natural flow and mutual support — where each person is said to bring out the best in the other. Dynamic aspects like squares (90°) and oppositions (180°) are read as points of tension that, when understood, can become engines of growth. Conjunctions (0°) are traditionally read as merging the energies of the planets involved.
Astro Precise calculates all Ptolemaic aspects with standard orbs — 8° for major aspects, 4° for minor ones — the real measured contacts between your two charts. The overall character above is read from the balance of those aspects — how many bring ease versus friction — rather than a single number pretending to score a relationship. The area bars show the elemental resonance between your key placements.
Keep Exploring the Real Sky
Astrological meaning is tradition, offered for reflection and entertainment — not advice, prediction, or scientific fact. The astronomy underneath is computed and checkable.