What is a Synastry Chart in astrology?

A synastry chart compares the birth charts of two people to evaluate relationship dynamics, emotional harmony, and mutual chemistry.

What are the most important planets for love in synastry?

Venus (romantic affection and values), Mars (attraction and passion), the Moon (emotional connection), and Sun (core life goals).

Can a challenging synastry aspect still result in a happy relationship?

Yes, challenging aspects like squares and oppositions often create magnetic attraction and catalytic personal growth when supported by open communication.

What information do I need for both people to run a synastry chart?

You need each person's birth date, exact birth time, and birth location — the same data required for an individual birth chart. Exact birth time matters most for placements like the Moon and Ascendant, which shift relatively quickly.

How is synastry different from comparing just sun signs?

Sun-sign comparison looks at one placement each. Synastry overlays both people's full charts and examines the angular relationships (aspects) between every pair of planets, giving a much more detailed — though still traditional, not scientific — picture of relationship dynamics.

Synastry Chart Calculator

Compare two birth charts to analyze relationship compatibility, romantic chemistry, and emotional harmony.

TL;DR: Synastry Chart Calculator analyzes cross-aspects and planetary connections between two individuals with 100% privacy.

PERSON A

PERSON B

Why Use This Tool?

Synastry Chart Calculator compares two people's full birth charts to see how their planets interact — a more detailed compatibility method than a simple sun-sign comparison, though still a traditional astrological framework, not a scientific prediction.

How to Use the Synastry Chart Calculator

Our Synastry Chart Calculator utilizes deterministic astronomical ephemeris formulas to calculate accurate planetary positions, signs, degrees, and aspects right inside your web browser.

Astrology & Personal Reflection Disclaimer

Astrological interpretations are provided for entertainment, personal reflection, and self-exploration. They do not constitute scientific fact, financial, medical, or relationship guarantees.

100% Client-Side Privacy Guarantee

All processing runs locally inside your browser using JavaScript and HTML5 APIs. Your data, files, and inputs are never uploaded to any remote server. Complete privacy by design.

Frequently Asked Questions

: A synastry chart compares the birth charts of two people to evaluate relationship dynamics, emotional harmony, and mutual chemistry.
: Venus (romantic affection and values), Mars (attraction and passion), the Moon (emotional connection), and Sun (core life goals).
: Yes, challenging aspects like squares and oppositions often create magnetic attraction and catalytic personal growth when supported by open communication.
: You need each person's birth date, exact birth time, and birth location — the same data required for an individual birth chart. Exact birth time matters most for placements like the Moon and Ascendant, which shift relatively quickly.
: Sun-sign comparison looks at one placement each. Synastry overlays both people's full charts and examines the angular relationships (aspects) between every pair of planets, giving a much more detailed — though still traditional, not scientific — picture of relationship dynamics.

Embed This Tool

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