Composite chart: the third chart born from two people
A composite chart is built from the midpoints of two birth charts. It does not describe two people — it reads the relationship itself as a living thing.
Calculate for freeCompositeA composite chart takes the midpoint of every planet in two birth charts: the exact middle between your Sun and theirs becomes the composite Sun. The result is not a real moment in the sky but a mathematically derived, symbolic chart — and it shows the identity of the relationship.
Synastry answers 'what happens between us'; the composite answers 'what is this relationship'. Two people can be individually compatible, yet if their composite carries a heavy Saturn-Moon square the relationship keeps wrestling with duty and distance.
Reading order in a composite
- Composite ascendant: the face the relationship shows and its first contact.
- Composite Sun and its house: why the relationship exists and where it spends energy.
- Composite Moon and its house: its emotional need, what makes it feel at home.
- Composite Venus: the relationship's love language and values.
- Composite Mars: its style of desire and conflict.
- Composite Saturn: the testing, duty and durability axis.
- The busiest house: which area of life the relationship concentrates in.
What the house placements say
A composite Sun in the 7th means the relationship exists as a partnership identity — marriage, formality and reciprocity run strong. In the 12th it is private, inward or built on sacrifice; invisible from outside, which can isolate the pair. In the 5th it breathes through play, creativity, flirtation and children.
Composite vs Davison
The composite is derived from midpoints and corresponds to no real time. The Davison calculates the actual moment halfway between both birth dates and coordinates, which is why a Davison chart can receive transits, be progressed, and show the relationship's timing. Read together, the composite tells you who you are and the Davison tells you when things happen.
What to avoid when interpreting
The most common mistake is treating one hard aspect as the relationship's fate. A composite Saturn square marks the test, not the ending — it points at where maturity is required. The composite is also never read alone; without synastry and both natal charts the picture stays incomplete.
Frequently asked questions
How is a composite chart calculated?
The ecliptic longitude of each planet in both charts is averaged to a midpoint. Houses are usually built from the midpoint of the two birthplaces. AstroKolly does this automatically from two sets of birth data.
Which matters more, composite or synastry?
They answer different questions. Synastry shows attraction and interaction; the composite shows the relationship's character. A sound reading uses both.
Can a composite be read without an ascendant?
Planetary aspects can, but house placements require both birth times. Without times, keep the interpretation to the aspects.
Does a composite chart show a breakup?
No single placement shows a breakup. Composite Saturn, Uranus and 12th-house emphasis show strain; the outcome depends on how the two people handle those themes.