Composite & Davison Charts

Why these exist

A synastry chart compares two charts side-by-side. But sometimes you want a chart of the relationship itself — a single chart that behaves like a third entity, the "we" of the partnership. Composite and Davison are two ways to construct that.

They give different answers because they're built on different philosophies.

How to find them

Hamburger → WESTERN → Composite / Davison. Pick a saved partner chart; KarmaWheel returns both at once.

Composite Chart

Composite = the midpoint of corresponding planets.

For each planet, compute (longitude_A + longitude_B) / 2, accounting for the shorter arc (so two planets at 350° and 10° give a midpoint at 0°, not 180°).

The composite isn't a real chart of a real moment — it's a derived chart that represents the relationship's shared psyche. - Composite Sun — the relationship's purpose / vitality - Composite Moon — the emotional rhythm of the relationship - Composite Asc — how the relationship presents to the world

Davison Chart

Davison = a real chart cast for the literal midpoint between two births in time and space.

Date and time = average of the two birth moments (in JD)
Lat / lon = average of the two birth locations

Because the Davison is a real chart cast for a real moment, it has real planetary positions — none of the geometric midpointing artifacts of composite charts. Many practitioners prefer Davison for serious work; composite for intuitive synthesis.

How to read

KarmaWheel returns both:

Composite section

A table of midpoint positions for each planet. The most-watched points:

Composite Asc — face of the relationship
Composite Sun + Moon — relationship purpose + emotional core
Composite Venus + Mars — chemistry; tension and attraction

Davison section

Full chart for the midpoint moment + location. Read it like any natal chart, but interpret the placements as relationship-themes:

Davison Saturn in 7th = relationship requires structure / commitment
Davison Jupiter in 11th = relationship thrives on shared community / mutual growth

When to use each

Composite — intuitive, snapshot, fast read. Good for first- pass.
Davison — rigorous, real-chart. Good for deep work, predictive (Davison transits behave like natal transits).

Most practitioners use both and watch where they agree.

Pairing with synastry

Synastry + Composite + Davison = the 3-fold relationship layer:

Synastry — how each chart impacts the other
Composite — the shared psyche
Davison — the relationship-as-entity

For a major relationship (marriage, deep partnership), all three should be read.

Caveats

Geographic midpoint is computed as a simple lat/lon average. For partners born far apart (across hemispheres), the great-circle midpoint is more correct. KarmaWheel uses the simpler form; refinement is possible later.
Composite Asc assumes both charts have valid birth times. If either time is rectified or unknown, the composite Asc is unreliable.

Sources

Robert Hand, Planets in Composite (1975) — definitive composite text
Ronald Davison's Synastry: Understanding Human Relations Through Astrology — origin of the Davison chart