Free Composite Chart Calculator

A composite chart is a single symbolic chart for reading a relationship as a shared pattern. It is calculated by finding the midpoint between each pair of corresponding planets in two natal charts: your Sun and their Sun, your Moon and their Moon, and so on through every planet and point. The result is a third chart that astrologers read for the relationship's shared tone, emphasis, and growth areas.

The composite midpoint method was popularized by astrologer Robert Hand in his 1975 book Planets in Composite. Unlike synastry, which preserves both individual charts and shows how they interact, the composite chart merges them into a midpoint chart. The calculator computes the midpoint for each corresponding pair, including the Ascendant and house cusps when exact birth times are provided.

Start with the composite Sun. Its sign and house are commonly read as the relationship's core identity prompt and primary area of focus. A composite Sun in the 7th house, for example, centers the relationship around partnership and mutual commitment, while a 10th house Sun suggests the relationship has a public-facing quality or shared ambition. The composite Moon shows the emotional undercurrent: how both people feel when they're together and what the relationship needs to feel safe.

Angular planets, those near the composite Ascendant, MC, Descendant, or IC, often stand out in the relationship's expression. Venus or Jupiter angular can indicate a relationship others perceive as warm, generous, or fortunate. Saturn angular can feel heavy but may build lasting structure. The internal aspects between composite planets show whether the relationship's energies flow easily (trines, sextiles) or generate tension that drives growth (squares, oppositions). A composite chart with many squares is not automatically bad; it simply means the relationship pushes both people to evolve.

The composite Sunis commonly read for the relationship's core purpose and the identity it projects into the world. The composite Moonis read for emotional tone: what the relationship needs to feel secure and how both people may feel when they're together. Composite Venus shows how love and affection may be expressed between you: the style of tenderness, generosity, and aesthetic pleasure the relationship generates. Composite Mars governs how desire and conflict operate: whether friction is approached directly, passively, or productively. Composite Saturn can act as glue; its sign and house show where the relationship demands patience and structure, but also where it builds the most enduring foundation.

House placements matter as much as signs. A composite Venus in the 2nd house orients love around shared resources and security; in the 5th it's playful and expressive; in the 8th it's intense and transformative. Any planet in an angular house (1st, 4th, 7th, or 10th) will color the relationship's visible personality more than one tucked in a cadent house. For full sign-by-sign and house-by-house interpretations of every composite placement, visit our composite chart interpretation guide.