The relationship’s own chart.

A composite chart is not either person's chart — it's the midpoint of both. Each body's longitude is averaged across the two partners to produce a single chart that represents the relationship as its own entity. Composite Sun sign hints at the relationship's core identity; composite Moon at its emotional style; composite Venus at how it expresses affection; composite Mars at how it pursues, fights, and metabolizes friction.

Synastry asks 'how do these two people contact each other?' (planet-to-planet aspects between the charts). Composite asks 'what is the relationship's own personality?' (one chart of midpoints). They answer different questions, both worth knowing. Most practitioners read synastry first to map the dynamic, then read composite to feel the relationship's identity. Both are free; the interpretive narrative is genuinely distinct between them.

The composite Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn placements. Each gets a practitioner-written interpretation that reads the relationship as a single entity — not 'you two' but 'the third thing you make together.' A short synastry teaser; for the full inter-chart aspect map, run the synastry chamber separately. Free as of v2.215.

Because composite Moon shifts about 6.5° per hour of birth-time error (averaged across two partners). The Moon governs the relationship's emotional register; getting the Moon's sign right matters. Sun and the slower planets are more forgiving. If both partners have reliable times, the reading sharpens significantly. If one or both times are uncertain, treat the Moon placement as approximate and lean on the slower placements.

There's also the Davison relational chart, which uses the time-and-place midpoint between two births rather than the longitude midpoint. They often agree but can diverge in edge cases. This page uses the standard midpoint composite — the most widely-read technique, and the one worth knowing first.