The Synastry methodology

How compatibility works

How Synastry compares full birth charts and turns planetary relationships into a clear compatibility blueprint.

What Synastry compares

Synastry calculates a natal chart for each member from birth date, local birth time, birthplace coordinates, and time zone. It then compares the angular relationships between planets, nodes, chart angles, and houses. Astrologers call these relationships “aspects.”

The same scoring framework is applied consistently to each pair. It does not inspect messages, photographs, ethnicity, income, browsing behavior, or social-media data.

How to read the scores

Scores run from 0 to 100 and measure the relative strength of selected astrological alignment indicators. They are not percentages or predictions of relationship success. The modeled-pairing reference beside the overall score shows how unusual a result is within the current scoring system.

Overall alignment

A synthesis of the category scores, offering an at-a-glance view of how both charts work together across the full relationship blueprint.

Emotional safety

Patterns associated with comfort, care, vulnerability, and emotional responsiveness.

Attraction

Patterns traditionally associated with affection, desire, magnetism, and emotional chemistry.

Relationship stability

How well the relationship can stay connected and resilient through pressure, change, and conflict.

Communication

How thinking and expression styles may support understanding—or require more translation.

Long-term potential

Patterns associated with steadiness, commitment, responsibility, and resilience over time.

Growth potential

Where the connection may invite learning, perspective, or meaningful change.

Ease through conflict

How naturally the relationship can navigate tension, repair disagreements, and reconnect after conflict.

Modeled v9 reference

Across one million synthetic chart pairings, the median overall score was 51. Scores of 60+ appeared in 16.1375% of pairings, 70+ in 1.9405%, and 80+ in 0.0823%. These figures describe the scoring system—not real-world relationship outcomes.

Use the whole blueprint

Every score sits inside a larger chart story. Accurate birth data produces the clearest reading, and the category details reveal far more than the overall number alone. Use the blueprint to understand the connection’s gifts, growth edges, and questions worth exploring together.

Why the reading can change

A reading is recalculated when either member updates birth data or when the compatibility framework is refined. The full pattern matters more than a one- or two-point shift.