Synastry — Online Compatibility

What is Synastry

Synastry is the comparison of two natal charts with one another. The astrologer superimposes one person’s chart over another’s and examines which aspects form between their planets: where attraction arises, where tension exists, and where partners simply do not notice each other.

Unlike compatibility based on zodiac signs, synastry considers the entire chart: the Moon, Venus, Mars, the Ascendant, and the houses. This is why two Scorpios may get along wonderfully, while two couples with “ideal” sign compatibility may live entirely differently.

What Does Synastry Show for a Couple?

The most revealing connections in synastry are aspects between the Sun and Moon, between Venus and Mars, as well as contacts of personal planets with the partner’s Ascendant. Harmonious aspects bring ease and a sense of “belonging,” while tense ones add dynamism and attraction but require effort.

Houses are also examined separately: a partner’s planet falling into your 7th house operates differently than the same planet in your 12th house. This shows in which area of life the relationship manifests most strongly.

How Does Synastry Differ from a Composite Chart?

Synastry compares two separate charts and shows how partners influence each other. A composite chart is constructed as a mathematical midpoint of the two charts and describes the relationship as a separate entity with its own character and purpose.

In practice, they are read together: synastry explains the chemistry between people, while the composite shows where the couple is headed.

Is an Exact Birth Time for Both Partners Necessary?

For a basic analysis, birth dates alone are sufficient: aspects between slow and personal planets will be accurate. However, without an exact time, it is impossible to determine Ascendants and houses—half the information about the relationship.

If the time is known for at least one partner, the analysis becomes significantly more meaningful.

Does a Difficult Synastry Mean the Relationship is Doomed?

No. Tense aspects indicate areas where partners will need to compromise, not a verdict. Couples with very smooth synastry often break up due to a lack of dynamism, while couples with squares may stay together for decades if they recognize their friction points.