Composite chart calculator
A composite chart is a single chart created by taking the midpoints of the planetary positions in two people's birth charts. For example, if two people's Suns are at 10° Aries and 10° Gemini, the composite Sun falls at 10° Taurus, the midpoint of the shorter arc. This chart does not look at the two people separately; it interprets the relationship itself as a third entity. While synastry shows how two people affect each other, the composite chart describes what kind of character, purpose and themes the relationship has as a whole.
In the composite chart, the Sun shows the relationship's core purpose and identity, the Moon its emotional atmosphere, Venus its way of loving and attracting, Mars its shared energy and style of conflict, and Saturn its side of testing and endurance. The Ascendant and houses are calculated as well. In an alternative method called the Davison chart, the midpoints of the two birth dates, times and places are taken and a chart is cast for an actual moment. Like synastry, the composite chart does not determine the outcome of a relationship in advance; it shows the relationship's themes and tendencies symbolically.
