Composite Chart Calculator — The Midpoint Chart for Two

A composite chart is a third chart built from two people's natal charts. For each body from the Sun to Pluto, the engine finds the point exactly halfway between that body's positions in the two charts — the midpoint — and that ten-body table of midpoint positions is the composite. It is read as the chart of the pair: the shared Sun, the shared Moon, and so on, instead of two separate charts.

Because the methods conflict. The main schools disagree on what the composite ascendant even is — some take the midpoint of the two natal ascendants, others derive one from the midpoint Sun and Moon — and the two methods produce different charts. Facing a genuine disagreement between methods, the engine computes neither: what you get is the midpoint positions every method agrees on, presented plainly.

One row per body — the Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto — each with its midpoint sign and degree in the tropical zodiac, computed with Swiss Ephemeris. The table is the composite chart: ten midpoint positions, and deliberately no houses and no angles.

Synastry compares the two natal charts by their cross aspects: every contact between a body in one chart and a body in the other, with its orb and whether it is applying or separating. The composite instead merges the two charts into one by taking the midpoint of each body. Both are shown on this page — the composite table first, the cross-aspect grid below — and the full contact grid is the centerpiece of our synastry calculator.

No. The composite is geometry: midpoint positions computed from two birth times. Nothing in the calculation predicts outcomes, and this tool does not interpret the pair's future. A reading can weigh the midpoint chart against the two natal charts and say what the aspects mean — the calculator only shows the positions.

Vedic astrology does not use the midpoint composite; the standard compatibility comparison is Gun Milan (Kundli Milan), which scores two charts against the 36-guna system based on the Moon signs. If the Vedic approach fits the couple better, the Kundli Milan calculator on this site is the sidereal counterpart — the two systems measure compatibility differently, and both are legitimate.