Composite chart calculator
Merge two birth charts into one: the midpoint chart that astrologers read as the personality of the relationship itself.
Save both people and the comparison appears below.
How to read a composite chart
Start with the composite Sun: its sign and house describe what the relationship is for, the shared purpose that keeps you together. The composite Moon shows the emotional climate at home; composite Venus, how affection flows; composite Mars, how you act as a team and how you argue.
Planets near the composite Ascendant or Midheaven are highly visible to others: a composite Sun on the Midheaven often marks a couple known publicly together, or a business partnership. Tight aspects between composite planets matter too: Saturn touching the Sun or Moon is the classic signature of commitment and hard work.
A composite doesn’t replace synastry: it tells you what the “us” is like, not whether each person feels met by the other.
Questions people ask
What is a composite chart?
A composite chart is one chart for a relationship, made by taking the midpoint between each pair of matching planets in two birth charts (both Suns, both Moons, and so on). It describes the relationship’s own personality and purpose.
Composite vs synastry: which should I use?
Use synastry to see how two people affect each other, and a composite to see what the relationship is like as a unit, the “us”. Astrologers usually read both.
How are composite houses calculated?
We use the midpoint method throughout: the composite Ascendant and Midheaven are the midpoints of both people’s angles, and houses are Equal houses from that Ascendant. Both birth times are needed for the angles.
Why is our composite Venus in a sign neither of us has?
Midpoints can land anywhere between the two positions, including signs neither person has. That’s normal: the relationship has its own flavour.