Reading a synastry chart means checking how one person's planets land in the other's signs and houses, then weighing the aspects between them. Here's the exact step-by-step method, in order of what matters most.
To read a synastry chart, you overlay two birth charts and work through four layers in order: overall element balance, each person's planets in the other's houses, the inter-aspects between the two sets of planets, and finally the heavyweight Saturn and outer-planet contacts. Reading in that sequence keeps you from drowning in detail and ensures you weigh the contacts that actually matter for a relationship.
This is the same method an astrologer uses. If you already understand what a synastry chart is, this guide is the practical "now what do I do with it" companion.
Before any single aspect, get a feel for the two charts together:
This step tells you the "weather" of the relationship before you read the details.
This is the step beginners skip, and it's where synastry comes alive. Take Person A's planets and see which of Person B's houses they fall into — then reverse it.
Planets-in-houses answer where one person activates the other's life.
Inter-aspects are the angles between your planets and your partner's. Read them in this order of importance:
| Priority | Contact | What it governs |
|---|---|---|
| 1 | Sun ↔ Moon | Core recognition, "I get you" |
| 2 | Venus ↔ Mars | Physical and romantic chemistry |
| 3 | Moon ↔ Venus/Moon | Emotional safety and affection |
| 4 | Mercury ↔ Mercury | Communication and mental rapport |
for reflection & self-knowledge — not prescription.
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Then judge the quality of each aspect:
Saturn is the make-or-break planet of synastry. Saturn contacts create commitment, structure, and staying power — which is why they show up so often in marriages, even though Saturn can also feel heavy or restrictive. Pluto contacts intensify and transform; Neptune contacts romanticize (and sometimes blur reality); Uranus contacts excite (and destabilize).
These slow planets tell you whether the relationship has glue and depth, not just spark.
Holding all four layers in your head at once is the genuinely hard part — a full synastry read has dozens of contacts pulling in different directions.
Natal AI overlays both charts and synthesizes the whole picture into plain language, so instead of decoding "Venus square Saturn" you can simply ask, "Why do we keep having the same argument?" and get an answer that weighs every relevant contact at once.
