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Free Composite Chart Calculator
A composite chart is the chart of the relationship itself: every planet sits at the midpoint of the two birth charts. Enter both birth details and this free composite chart calculator computes the midpoint positions, the composite aspects and the composite angles from a NASA JPL ephemeris — and shows no invented score. Free, no sign-up.
Two birth details
Frequently asked
Questions, answered honestly
What is a composite chart?
The chart of the relationship itself: every planet, angle and house cusp sits at the midpoint of the two birth charts. It sketches what the two of you create together, as distinct from either person's own chart.
Is this the same as a Davison chart?
No. A Davison chart takes the midpoint time and place of the two births and casts a real chart for that moment. This tool uses midpoint longitudes only — the method is disclosed on the page, and the two are never mixed.
Why is there no score on a composite chart?
The five dimension scores on our compatibility cards come from synastry — aspects between two separate charts. That model does not transfer to a composite chart, so rather than invent a 0–100 number, this tool shows the positions and aspects themselves.
Do I need both birth times?
For the planets, no — with an unknown time we calculate a midday chart, as the other tools do. For the composite rising sign, Midheaven and houses, yes: they need both exact times, and without them they are honestly left out, not guessed.
Does a composite chart predict whether a relationship lasts?
No. It describes tendencies in a chart, for reflection and entertainment. It never decides medical, financial or life questions, and it is not a verdict on any relationship.
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Computed with our own engine on NASA JPL DE421 ephemeris data. Results are for reflection and entertainment — they describe tendencies in a chart, never medical, financial or life decisions.