Astrological compatibility explores how two people’s symbolic patterns interact. Sun-sign compatibility is a simple entry point, but synastry compares two complete natal charts. Relationship astrology also uses house overlays and combined charts to describe the character of a partnership. None of these techniques can verify a relationship’s quality or replace communication, consent and personal judgment.
From zodiac pairing to full-chart comparison
A comparison of Sun signs considers elements, modalities and the traditional qualities of each sign. It can suggest a common vocabulary, but it cannot account for the emotional style shown by the Moon, relationship needs associated with Venus, initiative associated with Mars or the condition of the seventh house. A richer comparison starts with each person’s chart separately and only then studies the contacts between them.
What synastry measures
In synastry, a planet in one person’s chart can form an aspect to a planet or angle in the other person’s chart. The same planetary meanings remain relevant, but the aspect operates between two individuals. A Venus–Saturn contact may be read as a conversation about affection and commitment; a Mercury–Mercury contact concerns communication. House overlays indicate where one person’s planets fall in the other’s houses. A difficult contact does not prove incompatibility, and a harmonious one does not guarantee it.
Composite and Davison charts
A midpoint composite chart calculates positions midway between corresponding factors in two natal charts. A Davison chart is cast for a midpoint in time and geographic position. Both are approaches to considering the partnership as a distinct subject, yet they use different constructions and require their own interpretive rules. Assess them alongside, rather than instead of, synastry and the original natal charts.
Explore Compatibility & Synastry
Use the topic guides within this section to explore definitions, interpretation methods and specific applications. Each guide is part of the wider Astrology encyclopedia; related pages are connected as the section expands.
Guides in this section
A Sun-sign comparison is a broad starting point. Complete relationship analysis moves to two natal charts, interchart aspects, house overlays and combined-chart methods, while keeping the people and their choices at the center.
- Zodiac Sign Compatibility — Sun-sign pairings, elements and modalities.
- Synastry & Interchart Aspects — Planet-to-planet contacts between two people.
- Composite & Davison Charts — Two different methods of combined relationship charts.
- Relationship House Overlays — One person’s planets in the other’s twelve houses.