Synastry Chart Calculator

What This Tool Shows

Synastry is the comparison of two birth charts to reveal relationship dynamics, compatibility, and karmic connections. By overlaying both charts, we see how each person's planets interact with the other's, creating a unique energetic exchange.

• Inter-Aspects - How one person's planets aspect the other's planets (conjunctions, trines, squares, oppositions between charts)
• House Overlays - Which life areas are activated when one person's planets fall into the other's houses
• Compatibility Scores - Overall harmony between elements, modalities, and planetary connections
• Karmic Indicators - South Node connections, Saturn aspects, and Pluto dynamics showing past-life ties
• Attraction Patterns - Venus-Mars dynamics, Sun-Moon connections revealing romantic chemistry
• Communication Style - Mercury connections showing how you understand and communicate with each other

Example Output Reference

The synastry chart displays both partners' planetary positions with aspect lines showing connections between the two charts. This creates a map of your relationship dynamics. This is an example reference only - your personal synastry requires both partners' exact birth data.

Your personalized synastry chart will be calculated with precision using both partners' specific birth data in the AstroMatrix app.

Example Interpretation Snapshot

When you generate your personal synastry chart in AstroMatrix, you receive detailed interpretations for every significant connection. Here's what a typical reading includes:

Partner A's Sun conjunct Partner B's Venus

This is one of the most harmonious aspects in synastry, creating natural affection and mutual appreciation. Partner B finds Partner A's core identity attractive and valuable, while Partner A feels genuinely loved and admired. This aspect enhances romantic attraction and promotes harmony in the relationship.

Partner A's Mars square Partner B's Moon

This challenging aspect creates dynamic tension between action and emotion. Partner A's assertiveness may sometimes feel aggressive to Partner B's emotional sensitivity. However, this aspect also generates passionate intensity and can fuel a deeply magnetic connection when both partners learn to balance directness with emotional awareness.

Partner B's Venus in Partner A's 7th House

When one person's Venus lands in the other's house of partnership, it directly activates relationship potential. Partner A experiences Partner B as an ideal romantic partner, embodying qualities they seek in committed relationships. This overlay enhances the desire for formal partnership and marriage.

Partner A's North Node conjunct Partner B's Sun

This powerful karmic indicator suggests Partner B represents Partner A's evolutionary path forward. The Sun person illuminates the direction the North Node person needs to grow toward. This relationship has a destined quality, often feeling significant from the first meeting.

These interpretations synthesize inter-aspects and house overlays to reveal the complete relationship dynamic between both partners.

Calculation Method & Options

AstroMatrix calculates synastry charts using professional-grade Swiss Ephemeris data for both partners. The calculator requires accurate birth information for both individuals and offers the same flexibility as individual birth charts:

Zodiac Systems

Both charts use consistent zodiac systems - either tropical (Western) or sidereal (Vedic). Mixing systems between partners is not recommended. Most Western astrologers interpret synastry using the tropical zodiac.

House Systems

Select from Placidus, Whole Sign, Equal, Koch, or other house systems. The house system affects house overlays - which life areas are activated in each person's chart by the other's planets.

Aspect Orbs

Inter-chart aspects use slightly tighter orbs than natal aspects. Major aspects (conjunction, opposition, square, trine, sextile) typically use 6-8 degree orbs for synastry, ensuring only the most significant connections are highlighted.

Birth Time and Data Accuracy

Why Both Birth Times Matter

Accurate birth times for both partners enable precise house overlay analysis. When Partner A's planets fall in Partner B's houses, it shows which life areas are activated. Without accurate birth times, you can still analyze inter-aspects but house overlays will be approximate.

Unknown Birth Time for One Partner

If one partner lacks an exact birth time, you can still generate valuable synastry focusing on sign-to-sign planetary aspects. Use a noon chart for the partner with unknown time. You'll miss house overlay information but still see planetary connections.

Long-Distance Relationships

Birth locations affect each person's chart independently. Even partners born in different countries or time zones can have accurate synastry charts. We automatically handle timezone conversions and geographic coordinates for both locations.

Data Privacy

Both partners' birth data is required for calculation. Ensure you have consent before using someone else's birth information for synastry analysis.

Explore More Astrology Tools

Deepen your cosmic understanding with these related astrological calculators and reports: