Free Composite Chart Calculator
Merge two birth charts into one composite chart — the chart of your relationship itself. See your composite Sun, Moon, Venus, and houses, with a personalized AI reading. No signup.
Enter both people's birth details. The composite planets are the midpoints of your two charts; birth times add the composite houses and Ascendant.
What Is a Composite Chart?
A composite chart is a single chart created from the midpoints of two people's birth charts. Instead of comparing you as two individuals, it describes the relationship itself as its own entity — read like a birth chart of the couple.
Where synastry overlays two separate charts, a composite blends them into one. Each composite planet sits exactly halfway between where that planet falls in each person's chart, producing a brand-new chart that belongs to the relationship.
You read a composite chart much like a natal chart — its Sun, Moon, Venus, houses, and aspects describe the purpose, emotional core, and character of the bond between you.
How Is a Composite Chart Calculated?
A composite chart uses the midpoint method: each composite planet is placed at the exact midpoint between the same planet in the two birth charts. Your composite Sun sits halfway between your Sun and your partner's Sun, and so on for every planet.
Because it is built from midpoints, the composite is a mathematical blend rather than a real moment in time. It does not correspond to any actual date — it is a symbolic chart of the relationship.
When both birth times are known, the composite also has houses and an Ascendant, calculated from the midpoint of the two charts' angles, which deepen the reading.
Composite Sun, Moon, Venus & Ascendant
The core placements that define the relationship.
Composite Sun
The core identity and purpose of the relationship — what it is fundamentally about and the direction it is growing toward.
Composite Moon
The emotional heart of the bond — how the relationship feels, what makes it feel safe, and its instinctive emotional rhythm.
Composite Venus
The love and values of the relationship — how affection is expressed and what the two of you cherish together.
Composite Ascendant
How the relationship presents to the world — the first impression you make as a couple and the vibe others pick up.
Composite Houses
The house a composite planet falls in shows where the relationship's energy is focused. A composite Sun in the 10th house points to a partnership built around shared goals and public life; in the 4th, around home and family.
Composite houses only exist when both birth times are known, since they depend on the angles of the two charts. Without times, you still get the composite planets and their aspects, but not the houses.
Composite Chart vs Synastry
Two different ways to read a relationship.
| Synastry | Composite | |
|---|---|---|
| What it is | Two charts overlaid | One merged midpoint chart |
| Question it answers | How do we interact? | What is the relationship itself? |
| Method | Cross-aspects between the two charts | Midpoint of each planet pair |
| Read as | Two people in dialogue | A single chart, like a couple's birth chart |
| Best for | Chemistry, friction, dynamics | The relationship's identity and purpose |
Can You Make a Composite Chart Without a Birth Time?
Yes, for the planets. The composite Sun, Moon, and other planets come from the midpoints of the two charts and can be calculated without birth times. But without exact times you lose the composite houses and the composite Ascendant.
If either birth time is unknown, we default to noon and show the composite planets and aspects, flagging that the houses and Ascendant are unavailable. Add both times for the complete composite chart.
Composite vs Davison Chart
The composite chart is a mathematical blend — the midpoints of two charts, not a real moment. A Davison chart is different: it is cast for the actual midpoint in time and space between two births, producing a real date and place.
Both describe the relationship as an entity, and many astrologers compare them.
Ready to read your relationship?
Generate your composite chart now, or see the full compatibility picture with synastry and more.