Synastry Calculator

Synastry compares two birth charts: the angles between one person's planets and the other's, where each person's planets fall in the other's houses, and the composite chart (the midpoints of both charts), which describes the relationship itself. It works for partners, friends and business partners alike.

Person 1

First name (optional)

Month

Day

Year (AD)

Birth time (optional)

Birth place (quick pick)

Latitude (N +, S −)

Longitude (E +, W −)

Time zone at birth (UTC offset, hours)

Person 2

First name (optional)

Month

Day

Year (AD)

Birth time (optional)

Birth place (quick pick)

Latitude (N +, S −)

Longitude (E +, W −)

Time zone at birth (UTC offset, hours)

Birth times are optional; without them we leave out the Ascendant and house overlays. Empty time zones are filled from your browser for that date. Nothing you enter is stored.

About synastry

Astrologers have compared charts for centuries; the modern approach, built by writers such as Stephen Arroyo, Liz Greene, Ronald Davison and Robert Hand, looks at three layers: the aspects between two charts, the houses where one person's planets land in the other's chart, and the composite chart. This calculator uses the tropical zodiac, Placidus houses and the five major aspects.

Synastry Calculator

About synastry

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