If you are searching for a composite chart that shows what your relationship truly is—not just how you compare—start here. This free composite chart calculator blends two birth profiles into one unified relationship chart using the midpoint method: merged planetary positions, major aspects, and house placements in a single biwheel. A composite chart is not a comparison; it is the relationship's own chart.
A composite chart blends two natal charts into one unified chart by calculating the midpoint of each planet, house, and angle. Unlike synastry—which keeps both people visible and compares them—a composite chart merges their positions into a single third chart that describes the relationship as its own entity. Read it like a natal chart, but understand: this chart belongs to the relationship, not either person.
Synastry answers "how do your planets interact?" by comparing chart to chart. A composite chart answers "what is this relationship?" by merging both charts into one. Most astrologers use both: synastry for understanding individual dynamics and friction, composite chart for grasping the bond's core identity. Start with synastry for compatibility; use composite chart to understand what your partnership stands for.
Enter two birth dates, optional times (defaults to 12:00 local), locations, and timezones—then calculate. The tool finds the midpoint longitude for each of the ten classical planets, places them in houses using the midpoint Ascendant, and displays a biwheel with a sortable aspect table. Tighter orbs mean stronger relationship themes.
After your composite chart, open synastry to see how each person individually experiences the relationship. Then check astrocartography to find which cities amplify your bond's energy. Three tools, one workflow: composite chart for what the relationship is, synastry for how each person lives it, maps for where it thrives.
Start with the composite Sun sign—it describes the relationship's core identity and direction. Then check the Moon sign for emotional tone and security needs you share. Venus shows what draws you together and what you value jointly; Mars reveals shared drive and passion. Finally, scan the aspect table for any planet within 3°: conjunctions fuse energies so completely they define the relationship's character, while oppositions create the push-pull that keeps the bond dynamic. Saturn's sign and house in the composite chart signals where the relationship asks for commitment and patience—a strong composite Saturn often means longevity.
Built for clarity: fast dual-profile input, midpoint calculations you can trust, and a direct path from composite chart to synastry or geographic maps.
Four steps from birth data to a complete composite chart.
Everything you need to generate and read a composite chart, in one page.
Mathematical midpoint longitudes for all ten classical planets—the industry-standard approach for composite charts.
Both natal charts displayed together with composite midpoints clearly overlaid for an at-a-glance relationship picture.
Conjunction, opposition, square, trine, and sextile—sorted by orb so the strongest relationship dynamics surface first.
Consistent house system across composite, natal, and synastry tools for a coherent cross-tool reading experience.
Switch to synastry using the same birth data immediately after viewing your composite chart—no re-entry needed.
Available in English, Chinese, Spanish, Italian, Portuguese, and German—same accurate calculations in every language.
Common questions about composite charts and how to use this calculator.
Composite chart shows what the relationship is. Synastry shows how each person experiences it. Astrocartography maps reveal where your relationship energy feels strongest on Earth.
