Composite chart calculator
Each planet is the shorter-arc midpoint of the two natal positions. Houses follow the midpoint Ascendant in whole sign. This is a relationship chart, not a Davison (midpoint in time) chart.
Enter both charts, then calculate — the overlay wheel draws itself.
Composite vs Davison
This calculator uses planetary midpoints (the shorter arc between each pair of natal longitudes) and a midpoint Ascendant with whole-sign houses. A Davison chart instead takes the midpoint in time and space and computes a real sky. Both are used in relationship work; they are not the same chart.