Synastry Calculator
Explore Relationship Compatibility
Compare two birth charts to discover relationship compatibility. Analyze the planetary aspects between partners.
About the Synastry Calculator
Synastry is the art of relationship astrology. By comparing two birth charts, we can see how the planets in one person's chart interact with the planets in another's. These interactions reveal areas of attraction, harmony, tension, and growth potential in the relationship.
Our synastry calculator overlays two charts and calculates all inter-chart aspects—the angular relationships between planets in Chart A and planets in Chart B. Strong aspects like conjunctions, trines, and sextiles often indicate compatibility, while squares and oppositions may point to challenges that can lead to growth.
Whether you're exploring a romantic relationship, friendship, or business partnership, synastry provides insights into the cosmic chemistry between two individuals.
Features
- Bi-wheel chart overlay visualization
- Complete inter-chart aspect analysis
- Composite chart generation
- Compatibility scoring by planet and aspect type
- Detailed synastry interpretations
- Venus-Mars connections for romantic compatibility
- Moon-Moon aspects for emotional compatibility
- Saturn aspects for long-term stability
How to Use
- Enter Person A's birth date, time, and location
- Enter Person B's birth date, time, and location
- Click "Compare Charts" to generate the synastry analysis
- Explore the bi-wheel overlay and aspect grid
- Read the compatibility interpretations
Frequently Asked Questions
What is synastry in astrology?
Synastry is the comparison of two birth charts to analyze relationship compatibility. It examines how the planets in one person's chart aspect (form angles with) the planets in another person's chart, revealing areas of harmony, attraction, and potential challenges.
What are the most important synastry aspects?
Key synastry aspects include Sun-Moon contacts (emotional understanding), Venus-Mars aspects (romantic and physical attraction), Moon-Moon aspects (emotional compatibility), and Saturn aspects (longevity and commitment). The aspects between personal planets (Sun, Moon, Mercury, Venus, Mars) are generally most significant.
What is a composite chart vs synastry?
Synastry compares two separate charts and their interactions. A composite chart creates a single chart by calculating the midpoints between the same planets in both charts. The composite represents the relationship itself as its own entity, while synastry shows how two individuals interact.
Can synastry predict relationship success?
Synastry reveals the dynamics and potential of a relationship, but it cannot guarantee success or failure. Challenging aspects can lead to growth and passion, while harmonious aspects require effort to avoid complacency. Free will and commitment matter more than chart compatibility.