Free synastry chart calculator

Enter two birth charts, get a full compatibility map — free and without creating an account. The calculator is in final testing and launches here soon.

What synastry is

Synastry is the branch of astrology that compares two birth charts to describe how two people experience each other. Instead of reading one chart in isolation, it overlays them: where your Venus lands in their chart, how their Mars angles to your Moon, whose Saturn sits on whose Sun. Astrologers read those contacts — called aspects — as the texture of the relationship: the easy flow, the heat, and the friction.

What the report will show

• Inter-chart aspects — conjunctions, trines, sextiles, squares and oppositions between your planets and theirs, with plain-language interpretations
• House overlays — which areas of your life the other person's planets activate
• Element & modality balance — the overall temperament of the pairing at a glance

What you'll need

Birth date, time, and place for both people. Exact birth time matters most for house overlays and Moon aspects — if a time is unknown, the calculator will still read the planet-to-planet aspects that don't depend on it, and will tell you which parts of the report to take with a grain of salt.

Astrology content on this site is for entertainment and self-reflection. It is not advice, and no chart can decide a relationship for you.