Composite Chart Calculator: Your Relationship's Own Birth Chart
Enter two sets of birth details and we'll merge them into a single composite chart — the birth chart of your relationship itself — with its core placements interpreted.
Enter both birth details
Synastry Chart Calculator
Compare two birth charts to explore relationship compatibility and cosmic connections
Why the Composite Chart Matters
When two people come together, they create a third thing: the relationship itself. The composite chart is the birth chart of that third entity — an energy field that shapes both partners and has its own purpose, mood, and direction.
Unlike a personal chart, no one was born at the composite moment. Yet astrologers read it as one of the most revealing tools in relationship astrology, because it describes what the partnership is for — not just who two people are apart.
What Is a Composite Chart?
A composite chart is a single chart built from the midpoints between two people’s planets — the point halfway between their two Suns becomes the composite Sun, and so on for every planet.
For example, if one person’s Sun is at 13° Scorpio and the other’s is at 13° Capricorn, the composite Sun falls at their midpoint: 13° Sagittarius. Every planet is merged the same way, producing a complete chart you can read like any natal chart.
Because it is a mathematical construct, the composite chart has no real date or place — it exists only as the relationship’s astrological blueprint. That is exactly what makes it powerful: it isolates the partnership from the two individuals.
Composite vs. Synastry vs. Davison
These three techniques answer different questions about a relationship. Use them together for the full picture.
Composite
Midpoints of each planet pair. Describes the relationship as its own entity — its purpose and identity.
Synastry
Overlays two charts to compare them. Describes the live chemistry — how you affect and attract each other.
Davison
Midpoint in time and space between both births. A real chart for the couple as one — a documented addition coming soon.
How to Read Your Composite Chart
How to Use the Composite Chart Calculator
Creating your relationship’s chart takes a minute — and no account.
- 1Enter the first person’s birth date, time, and city. An accurate birth time matters, because it sets the Ascendant and houses.
- 2Enter the second person’s details the same way. This can be a partner, friend, family member, or business collaborator — any two people.
- 3Reveal your composite chart. You’ll see the full wheel, the core placements, and an interpretation of every composite planet.
Composite Planets Through the Signs
Once you run the calculator, every composite planet is interpreted through its sign — from the composite Sun’s purpose to the composite Mars’ drive — so you can read the whole relationship, placement by placement.