COMPOSITE NATAL CHART
Composite Natal Chart Calculator
Two birth records
Composite result
LOADING MODELThe chart between two charts.
Enter complete birth records to calculate midpoints for the Sun through Pluto and list close major aspects.
ASPECT REFERENCE
How the major aspects are read
| Aspect | Angle | Working meaning |
|---|---|---|
| Conjunction | 0° | Two functions act from the same point and need a shared expression. |
| Sextile | 60° | A usable opening that develops through choice and practice. |
| Square | 90° | Friction that asks for adjustment, effort, or a new method. |
| Trine | 120° | A fluent connection that can support ease, skill, or familiarity. |
| Opposition | 180° | A polarity that becomes clearer through balance and response. |
The results list only these five aspect types when their calculated separation is within a 3° orb. Astrology is a symbolic interpretation system, not a scientific method of prediction.
THE CALCULATION
Midpoints, stated plainly.
For each listed body, this calculator computes tropical geocentric longitude for both birth moments with a locally bundled Swiss Ephemeris model. It then takes the shortest-arc midpoint between those two longitudes. The result is a midpoint composite chart, not a Davison chart.
Dates from 1 January 1800 through 31 December 2399 are accepted. Birth time and UTC offset are required because the Moon can move substantially within a day. The tool does not calculate houses: those require a chosen place and house system, and this page deliberately does not infer either.
The bundled model runs locally in your browser. It does not send birth details to a server, use a preset date table, or query a city database.
COMMON QUESTIONS
Use the result well.
What is a composite natal chart?
It is a symbolic relationship chart built from the midpoints between two natal-chart longitudes. This calculator shows the planetary midpoint layer and major aspects among those midpoint positions.
Is this a Davison chart calculator?
No. A Davison chart uses a midpoint in time and location. This page uses the midpoint composite method and states that distinction before you calculate.
Why might another composite chart differ?
Check both recorded birth times, the UTC offsets in force on the dates, the zodiac type, and whether the other page uses midpoint composite or Davison methodology.
Where can I calculate an individual chart?
Open the natal chart calculator for an individual chart before comparing two records.