Real synastry
Synastry calculator
Sun-sign compatibility is only one of twelve pieces. Synastry crosses the two full natal charts: Sun, Moon, Venus, Mars and every other planet of each person, the aspects they form with each other and, if you know the time, the houses each one falls in.
How it works
Enter each person’s birth date. Time and city are optional, but with them the Ascendant, the precise Moon and the houses are calculated.
The engine computes both charts with Swiss ephemeris, measures the aspects between planets (conjunction, opposition, trine, square, sextile) and weighs them by orb and by planet.
You get a score by area (love, communication, passion and longevity), the main aspects explained and the couple’s composite chart.
Frequently asked questions
- What is the difference between synastry and sign compatibility?
- Sign compatibility compares only each person’s sun sign: twelve options per side, 144 combinations. Synastry compares the two full natal charts, with the exact position of every planet on the day of birth, so two couples with the same pair of signs can get very different results.
- Do I need the birth time?
- It is not required. Without a time, the planet-to-planet aspects, which are the heart of synastry, are still calculated. With a time you also get the Ascendant, the houses and the precise position of the Moon, which changes sign every two and a half days.
- What is the composite chart?
- It is a single chart built from the midpoints between both people’s planets. It describes the relationship as an entity of its own: how it shows itself to the world, what nourishes it and what tests it.