Reading a composite chart
Read a composite like a birth chart, but for the couple. The composite Sun is what the relationship is for, the thing that makes it feel alive. The composite Moon is its emotional weather: how it feels to be inside it on an ordinary Tuesday. Venus describes how affection is shown and what the two of you enjoy together. Saturn shows the duties the relationship takes on and where it feels the strain.
The house a planet falls in tells you where that energy is spent. A composite Sun in the 4th house tends to make home and family the center of things. In the 10th, the couple is often visible: working together, known as a pair.
Aspects inside the composite
Unlike synastry, the aspects here are between the composite’s own planets. A composite Moon square Saturn shows a relationship that takes feelings seriously and sometimes too seriously. A Venus trine Jupiter composite tends to be generous and fun. The calculator lists the strongest three with a short reading and the full table underneath.
Why the midpoints can surprise you
Two people with Suns in Aries and Libra, opposite signs, get a composite Sun in Cancer or Capricorn, a sign neither of them has. That is normal. The composite often brings out qualities the relationship has that neither person shows alone, which is one reason couples find it oddly accurate.
Accuracy
Planets come from astronomy-engine, accurate to well under an arcminute. Each planet takes the nearer midpoint, the convention most astrology software follows. Birth places come from GeoNames, so time zones and daylight saving are handled for the date you were born.
Questions people ask
What is a composite chart?
A single chart made from two. Each planet is placed at the midpoint between where it sits in the two birth charts, so the composite Sun is halfway between both Suns. Astrologers read it as the chart of the relationship itself.
How is it calculated?
With the midpoint method. For every planet we take the nearer of the two midpoints between the two positions. The composite Ascendant is the midpoint of the two Ascendants, and houses are counted as Whole Sign houses from it.
Composite chart or synastry: which should I look at?
Both, for different questions. Synastry shows what each of you sets off in the other. The composite shows what the relationship is like from the outside and what it seems to be for. This page shows the composite first and the synastry underneath.
Why is there no Ascendant in my composite?
The composite Ascendant needs both birth times. With one or both missing, the planets are still placed correctly, but the Rising sign and houses are left out rather than guessed.
Is this the same as a Davison chart?
No. A Davison chart is cast for the midpoint in time and space between two births and is a real moment of sky. The composite uses midpoints of positions. They often agree on the Sun and differ elsewhere.