Synastry online: compatibility from birth charts

What synastry is

Synastry lays two birth charts over each other. One person’s planets fall at particular angles to the other’s, and those angles read as the character of the bond: a conjunction intensifies, a trine or sextile brings ease, a square or opposition creates the tension that produces both attraction and conflict.

The key pairs in a relationship reading are Sun to Moon (agreement between what someone wants and what they feel), Venus to Mars (attraction), Moon to Saturn (reliability against coldness) and Mercury to Mercury (how easily you talk). These produce the feeling of “it is easy with us” or “we keep tripping over nothing”.

Why this is not sign compatibility

A sign-compatibility table compares only the Sun — effectively the month of birth. Synastry involves every planet in both charts, so a “Leo and Scorpio” pair that the table calls difficult may well have soft Moon and Venus aspects and get along more easily than a pair the table calls perfect.

For a more precise result you need both birth times: the Moon moves about a degree and a half an hour, and without the time it is exactly the most sensitive aspects that come out approximate.

Frequently asked

Will synastry tell me if we will be together?

No. It shows the mechanics of the bond: where it is easy, where it grinds, what the attraction runs on. The decision stays with the people — hard aspects turn up in very steady couples and vice versa.

Can I use it for non-romantic relationships?

Yes, the method is the same for friends, parents and children, business partners. Only which planetary pairs matter most changes.

What if I do not know my partner’s birth time?

Aspects between the slow planets will still compute, but the Moon and the houses will be approximate. Put 12:00 — that gives an average for the day, but treat the lunar aspects with caution.