Free Astrology Compatibility Calculator

Synastry is the astrological technique of comparing two birth charts to understand relationship dynamics. It examines the angular relationships (aspects) between one person's planets and the other person's planets. Harmonious aspects (trines, sextiles) indicate ease and flow, while challenging aspects (squares, oppositions) indicate tension and growth areas.

The compatibility score (0-100) is calculated by analyzing all inter-chart aspects between the two birth charts. Harmonious aspects (trines, sextiles) contribute positively, challenging aspects (squares, oppositions) contribute negatively, and neutral aspects (conjunctions, quincunxes) add moderate weight. The score is normalized based on aspect strength (tighter orbs score higher).

Astrology highlights the energetic dynamics between two people, not deterministic outcomes. A high compatibility score indicates natural ease and understanding, while a lower score indicates more friction that requires conscious effort. Many successful relationships have challenging synastry, as tension can create passion and growth. Use the results as a tool for self-awareness, not a verdict.