Synastry & Compatibility Calculator
Compare two birth charts to see the real astrological chemistry between you. Birth time makes it sharper, but date and place are enough to start.
Synastry compares your two charts placement by placement. Birth time sharpens the Moon and adds the Ascendant; without it we use noon.
What synastry reveals
Synastry is the astrology of relationships. Instead of one chart, it lays two charts over each other and measures the aspects — the angles — between your planets and theirs. Those angles are the real chemistry: where you flow, where you spark, and where the friction that keeps things interesting lives. It works for lovers, friends, family and colleagues alike.
The aspects that matter most
This calculator focuses on the personal planets — Sun, Moon, Mercury, Venus and Mars — because they describe who you are day to day. A trine or sextile between them feels easy and supportive; a conjunction fuses your energies; a square or opposition creates the tension that fuels attraction and growth. No aspect is "bad" — the mix is what makes a relationship real.
Go deeper
Read the full meaning of your connection in the Love Compatibility & Synastry collection, or build the shared chart of your relationship with the composite chart calculator.