Synastry Calculator

What is synastry?

Synastry is the branch of astrology that studies how two people's birth charts interact. Instead of comparing just sun signs, synastry overlays both complete natal charts and studies every angle between every planet in one chart and every planet in the other. The result is a detailed map of the specific chemistry between two people, romantic, emotional, sexual, intellectual, karmic.

This is the technique professional astrologers use for couple consultations. It reveals why some relationships feel electric and others feel flat, why some fights never end and others are resolved by a single look, why some couples finish each other's sentences and others misunderstand the simplest things.

What synastry reveals

The most important synastry aspects

Not every planetary contact carries the same weight. These are the ones professional astrologers study first:

• Sun-Moon: core resonance. One of the most important aspects in any lasting relationship.
• Venus-Mars: sexual attraction and romantic chemistry. The engine of passion.
• Moon-Moon: how you soothe each other when things get hard.
• Sun-Ascendant: do you see each other as the person you want to be?
• Venus-Venus: do you love the same things, enjoy the same pleasures?
• Mercury-Mercury: do you actually understand each other when you talk?
• Saturn aspects: will this last? Saturn is the long-game planet.
• Pluto contacts: is this a transformative relationship or a passing encounter?

Synastry vs composite chart

These two techniques answer different questions. Synastry asks: how do we interact? It shows the back-and-forth between two individuals. Composite chart asks: what kind of entity is this relationship itself? It creates a single new chart from the midpoints of both birth charts, treating the relationship as its own being with its own destiny.

Professional astrologers use both. The Karmastro Oracle calculates them automatically when you enter two birth charts, so you get the full picture in one session.

Can synastry predict if we will stay together?

No, and anyone who promises that is selling something. Synastry shows what you are working with, not what you will do with it. A challenging synastry can become one of the great love stories of two lives if both partners grow into the lessons. A beautiful synastry can fizzle out fast if neither partner does any inner work. Astrology shows the deal; free will plays the hand.

What synastry is excellent for is self-awareness in relationship. When you understand why the same fight keeps happening, you can stop taking it personally and start working with it. That alone saves relationships.