Synastry compares two natal charts. A composite chart calculates midpoints between them. A Davison chart calculates a midpoint in actual time and geographic space. The methods answer different questions and should not be treated as interchangeable compatibility scores.
Quick Comparison
| Method | Calculation | Main question |
|---|---|---|
| Synastry | Two natal charts compared directly | How do these two people affect one another? |
| Composite | Midpoint of each pair of natal factors | How does the relationship operate as a shared system? |
| Davison | Midpoint birth time, date, and location | What does the relationship chart look like as a dated chart? |
What Synastry Shows
Synastry preserves both natal charts. It compares inter-chart aspects, house overlays, angles, and rulers.
It is best for questions such as:
- How do our emotional needs interact?
- Where is communication easy or strained?
- What life areas do we activate for one another?
- How do attraction, conflict, responsibility, and support move between us?
Read synastry first because neither relationship chart can replace the two actual people.
What A Composite Chart Shows
A midpoint composite creates a symbolic third chart. If one Sun is at 10° Aries and the other at 10° Gemini, one midpoint is 10° Taurus. Every matching pair is midpointed.
Robert Hand describes the composite as a chart of the relationship entity: the patterns that emerge when the two people function together. Composite houses, planets, and aspects are interpreted much like a natal chart, but the subject is the bond rather than either individual.
Because it is mathematical, the composite chart does not represent one literal sky moment.
What A Davison Chart Shows
A Davison chart averages the two birth dates, times, and locations. The resulting chart corresponds to a real astronomical moment and place, even though that moment is derived rather than an observed relationship beginning.
Practitioners often read it more like an event or natal chart and apply transits and returns to it. That does not make it inherently more accurate than a composite chart; it gives it a different calculation logic.
Why The Charts Can Disagree
A relationship may have supportive synastry but a pressured composite chart, or difficult synastry with a stable composite Saturn.
This is not automatically a contradiction:
- Synastry describes interaction between two people;
- Composite describes the pattern created together;
- Davison describes a derived relationship chart in time and space.
If the methods disagree, record the difference. Do not keep adding charts until one confirms the desired story.
Which Chart Should You Read First?
Use this order:
- Read both natal charts.
- Read synastry.
- Read the composite chart.
- Add Davison only if its distinct method serves the question.
- Use timing after the relationship structure is understood.
For an established relationship, also study the chart of an actual beginning, first meeting, wedding, business launch, or signed contract, when the time is reliable.
Can Any Chart Predict Marriage Or Breakup?
No single contact proves either. Saturn can correlate with duration, duty, fear, or constraint. Uranus can correlate with freedom or disruption. Venus and Jupiter can bring pleasure without practical durability.
Predictions require natal context, relationship charts, real behavior, and several timing factors. Even then, state uncertainty.
Recommended Reading
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- Robert Hand, Planets in Composite: Analyzing Human Relationships.
- Kevin B. Burk, Astrological Relationship Handbook.
- Stephen Arroyo, Relationships & Life Cycles.