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Free Composite Chart Calculator
Create a composite birth chart for two people and explore the astrology of your relationship as a single chart.
See What a Composite Chart Looks Like
Sample composite summary
Alex + Jordan
Your composite chart represents the relationship as a whole rather than either person individually.
Composite Sun
Aquarius 27°39'
Shared identity and purpose
Composite Moon
Pisces 24°20'
Emotional climate of the bond
Composite Rising
Scorpio 12°14'
How the relationship presents
Composite Venus
Capricorn 21°03'
Love, affection, shared values
One chart for the relationship
Major composite aspect
Moon Conjunction Mars
Orb 1°50' · Strong
Feeling and drive fuse — the emotional life of the bond is active, protective, and quick to heat.
What Is a Composite Chart?
A composite chart — sometimes called a composite birth chart or composite relationship chart — is created by taking the planetary midpoints of two natal charts. Instead of comparing person to person, you get one new chart that describes the relationship as its own entity in relationship astrology.
Where synastry asks how two people affect each other, the composite chart answers a different question: what is this relationship like when it becomes “us”? Shared purpose, emotional climate, affection, and long-term tone all show up in the composite placements.
An astro composite chart still uses familiar tools — signs, houses, and aspects — but every point is a midpoint between the two birth charts rather than a single birth moment.
How Does the Composite Chart Calculator Work?
Enter birth details for both people. We calculate each natal chart, then take the shorter-arc midpoint for every planet and sensitive point:
- 1
Person A + Person B
Two birth charts are calculated from precise planetary positions for each birth time and place.
- 2
Planetary midpoints
Composite Sun is the midpoint of both Suns; Moon of both Moons; and so on for Venus, Mars, and the rest.
- 3
One relationship chart
The result is a single wheel with positions, major aspects, and — when times are known — houses and angles.
Midpoints respect the zodiac circle. For example, planets at 350° and 10° meet near 0° Aries — not at 180°. That circular math is essential for a correct composite birth chart.
How to Read a Composite Chart
Free composite chart interpretation starts with the same order many astrologers use for a natal chart — but every placement describes the relationship, not one individual. Work top-down: identity, feeling, love, drive, commitment, then houses and aspects.
Composite Sun
The composite Sun is the relationship's center of gravity: shared purpose, the story you tell as a pair, and what “us” feels like when it is healthy. Sign shows style — steady, fiery, thoughtful, private — while house (when birth times are known) shows where that identity plays out, from home and work to romance or public life. Sun aspects color the whole chart: links to Moon soften purpose with feeling; links to Saturn make the bond more serious; links to Mars push it into action. Read the composite Sun before minor points so you do not lose the plot in detail.
Composite Moon
The composite Moon is the inner climate of the bond — comfort, mood, and what makes the relationship feel safe or raw. It is less about public image and more about private rhythm: how you unwind together, what triggers withdrawal, and whether care is spoken, practical, intense, or spacious. House placement points to the life area where emotional habits collect; aspects to Venus or Saturn often show whether softness and duty cooperate. When the Moon is ignored, even strong attraction can feel thin. When it is honored, the chart has a place to land.
Composite Venus
Composite Venus describes how the relationship gives and receives affection, beauty, pleasure, and shared values. It answers what loving feels like inside this chart — not only whether chemistry exists. Sign and house hint at the preferred love language of the bond: steady loyalty, playful talk, aesthetic partnership, or deep loyalty under pressure. Aspects to Mars raise heat; aspects to Saturn slow and test affection; aspects to Mercury tie love to conversation. Use Venus to read harmony and taste before you judge every hard aspect as “bad compatibility.”
Composite Mars
Composite Mars is desire, initiative, sexuality, and conflict style inside the relationship field. It shows how the bond moves when something matters — chase, defend, build, argue, or freeze. A vivid Mars does not mean the pair is doomed; it means heat needs a clean job. Watch Venus–Mars contacts for chemistry tone, Mars with Saturn for blocked or disciplined drive, and Mars with the Moon for how anger and need interact. In free composite chart interpretation, Mars is where you separate passion from chronic friction.
Composite Saturn
Composite Saturn marks commitment, boundaries, responsibility, and long-term pressure. It is the craft of staying: timelines, respect, repairs, and what the relationship must build to last. Hard Saturn contacts can feel heavy; easy ones can feel like reliable structure. Either way, Saturn is not a simple “no” to love — in composite work it often shows where maturity is required so the Sun and Moon can keep working. House placement tells you which life area asks for adulthood first: home, work, money, intimacy, or public role.
Then houses and aspects
After the five lights and personal planets, read houses for where the bond lives day to day, then major aspects for how those themes talk to each other — conjunctions fuse, trines ease, squares grow, oppositions polarize. Your calculator result follows this same order with your real placements.
After you calculate, the result panel walks the same order with your real placements — free composite chart interpretation included, no account required. For person-to-person contacts instead, read how to read a synastry chart or open the synastry calculator.
Composite Chart Houses
When both birth times are known, composite house cusps show where the relationship “lives” — identity, home, work, intimacy, and more. That is different from synastry house overlays, which map one person’s planets into the other person’s houses.
| House | Composite meaning |
|---|---|
| 1st | Relationship identity |
| 2nd | Shared values and resources |
| 3rd | Communication |
| 4th | Home and emotional foundation |
| 5th | Romance and creativity |
| 6th | Daily routines |
| 7th | Partnership |
| 8th | Intimacy and shared resources |
| 9th | Growth and beliefs |
| 10th | Public role and goals |
| 11th | Friendship and shared vision |
| 12th | Hidden and unconscious patterns |
Composite Chart Aspects
Major aspects inside the composite chart describe how relationship themes cooperate or clash. Conjunctions fuse; trines and sextiles ease; squares and oppositions demand growth and awareness.
After you calculate, your strongest composite aspects appear with orb and a short interpretation — more useful than a generic aspect encyclopedia alone. For person-to-person contacts instead of aspects inside one midpoint chart, see synastry aspects.
Conjunction
Themes fuse
Sextile
Opportunity
Square
Tension / growth
Trine
Natural flow
Opposition
Polarity
Composite Chart vs Synastry
| Synastry | Composite | |
|---|---|---|
| Method | Compare two birth charts | Calculate planetary midpoints |
| Chart | Two charts shown together | One relationship chart |
| Main question | How do we affect each other? | What is this relationship like? |
| Best for | Attraction, compatibility, interactions | Relationship identity and dynamics |
Composite chart compatibility is a common search — but a composite is not mainly a percentage score. For interaction-style compatibility, use synastry; for the relationship's own character, stay with composite. Read the full comparison →
Want to compare your two charts directly? Calculate Your Synastry Chart →
Composite Chart vs Davison Chart
| Composite | Davison | |
|---|---|---|
| Calculation | Planetary midpoints | Midpoint in time and space |
| Chart | Symbolic midpoint chart | Chart for an actual midpoint date/time/location |
| Purpose | Relationship identity | Relationship as an event/context |
| Houses | Yes (with birth times) | Yes |
A free Davison chart calculator is not on this site yet. Composite remains the midpoint tool available today.
Composite Chart Calculator FAQ
- What is a composite chart?
- A composite chart is a midpoint chart built from two birth charts. It describes the relationship as one entity rather than comparing the two people planet-to-planet.
- How is a composite chart calculated?
- Each planet in person A is paired with the same planet in person B. The calculator finds the shorter-arc midpoint on the zodiac and builds a new set of placements — the composite birth chart.
- What does a composite birth chart show?
- It shows the relationship’s identity (Sun), emotional tone (Moon), affection (Venus), drive (Mars), communication (Mercury), commitment (Saturn), plus houses and aspects when birth times allow.
- Do I need exact birth times for a composite chart?
- Planet signs and most aspects work without exact times. Composite Ascendant, Midheaven, and houses need reliable birth times for both people.
- Can I calculate a composite chart without birth times?
- Yes. Check “I don’t know the exact birth time” for either person. You still get planetary midpoints and major aspects. Ascendant, Midheaven, and houses need reliable times to show with confidence.
- What is the difference between synastry and a composite chart?
- Synastry compares two charts to each other. A composite chart creates one midpoint relationship chart. Many people use both.
- What is the difference between a composite chart and a Davison chart?
- Composite uses planetary midpoints. Davison casts a real chart for the midpoint in time and geographic space between the two births.
- Does a composite chart show compatibility?
- It shows what the relationship is like — tone, purpose, and how the bond works from the inside — not a single compatibility percentage. For how two people affect each other, use the free Synastry Chart Calculator on the home page.
Related Tools
- Synastry Chart CalculatorCompare two birth charts for aspects, house overlays, and scores.
- Free Synastry ReportA plain-language reading of your strongest relationship patterns.
- Synastry AspectsHow planet-to-planet contacts shape chemistry and friction.
- Synastry HousesWhere each person’s planets land in the other’s chart.
- How to Read a Synastry ChartA practical order for aspects, planets, and overlays.
- Synastry vs CompositeWhen to compare two charts versus blend them.