Synastry reads the chemistry of a relationship by overlaying two birth charts. Whose planet falls into whose house, which aspects create attraction, which ones describe the recurring friction — all visible in a single map.
What is synastry?
Synastry is the comparison of two natal charts through the aspects they form to each other and the houses their planets fall into. It doesn't produce one compatibility number — it maps different layers: emotional safety, sexual attraction, communication, long-term commitment.
Venus–Mars contacts describe attraction, Moon–Moon and Moon–Venus links emotional resonance, Mercury aspects communication, and Saturn aspects durability and the balance of responsibility.
How to read compatibility
Easy aspects (trines, sextiles) create comfort but rarely hold a relationship together on their own. Squares and oppositions create tension — and that tension is often the source of both attraction and growth. Healthy relationships usually show a balanced mix.
House overlays are the most practical layer: one person's Sun in the other's 7th house makes partnership a core theme; in the 12th house, privacy, sacrifice and unconscious bonds come forward.
Who is it for?
People trying to understand a new connection, long-term couples decoding a repeating argument, and anyone curious about friendship or business-partner compatibility.
Frequently asked questions
Do both birth times matter for synastry?
Planetary aspects can be calculated without them, but house overlays and the exact Moon degree require both birth times.
Does a high compatibility score mean a happy relationship?
No. The score summarises the intensity and flow of the dynamic; the quality of the relationship depends on awareness and effort from both people.
How is synastry different from a composite chart?
Synastry compares two charts, while a composite builds a single 'relationship chart' from the midpoints of both.