Star Sign Compatibility Calculator

Expert Reviewer: Astro-Analyst Jane Doe, Certified Astrological Practitioner (CAP)

Welcome to the ultimate Star Sign Compatibility Calculator. Whether you’re curious about a romantic partner, a business colleague, or a friend, this tool provides an insightful score based on the foundational elements and modalities of the Zodiac. Discover your cosmic connection today!

Select Your Zodiac Sign (Sign One):

Select Partner’s Zodiac Sign (Sign Two):

Compatibility Score:

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Based on Elemental and Modality analysis.

Star Sign Compatibility Scoring Formula

Compatibility Score (C) is derived from two primary components: Elemental Affinity (E) and Modality Synergy (M).


                    C = Base Score + E + M
                    


                    Elemental Affinity (E):
                    

                        E = +30 if Signs have the Same Element (Trine or Conjunction)
                    

                        E = +25 if Signs have Complementary Elements (Fire/Air or Earth/Water)
                    

                        E = +15 if Signs are in Opposition (Different Element/Modality)
                    

                        E = +0 for Challenging/Square relationship.
                    


                    Modality Synergy (M):
                    

                        M = +10 if Signs have Different Modalities (Cardinal, Fixed, Mutable)
                    

                        M = -10 if Signs have the Same Modality (Creates friction/power struggle)

Source: Astrology Compatibility Principles

Variables

To use the calculator, you only need to input the two variables below:

Sign One: The zodiac sign of the first individual. This determines their core element (Fire, Earth, Air, Water) and modality (Cardinal, Fixed, Mutable).
Sign Two: The zodiac sign of the second individual. This is compared against Sign One to establish the core relationship dynamics.

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What is Star Sign Compatibility?

Star sign compatibility, often called synastry, is an astrological technique used to determine the harmony between two people based on the relationship between their sun signs. While a full synastry reading is complex, involving many planets, the sun sign compatibility calculator provides a reliable baseline by focusing on two key astrological components: the four Elements and the three Modalities.

The Elements (Fire, Earth, Air, Water) represent fundamental energies and temperaments. Fire signs seek action, Earth signs seek stability, Air signs seek connection, and Water signs seek emotional depth. Compatibility often thrives between signs of the same element (trine aspect) or complementary elements (e.g., Fire and Air, which fuel each other).

The Modalities (Cardinal, Fixed, Mutable) describe how signs initiate, maintain, and adapt to change. Cardinal signs are initiators, Fixed signs are stabilizers, and Mutable signs are flexible adjusters. Conflict often arises when two people share the same modality (e.g., two Cardinal signs fighting for leadership), while differing modalities typically create a balanced partnership.

How to Calculate Star Sign Compatibility (Example)

Let’s use an example to show how a relationship between an Aries (Fire, Cardinal) and a Libra (Air, Cardinal) is scored:

Identify Core Components: Aries is Fire and Cardinal. Libra is Air and Cardinal.
Determine Elemental Affinity (E): Fire and Air are complementary elements. Fire is fueled by Air, creating an attractive and intellectual match. This relationship earns an Elemental Affinity score of E = +25.
Determine Modality Synergy (M): Both signs are Cardinal. This means both are natural leaders who prioritize initiating action. This can lead to power struggles. This same-modality relationship earns a Modality Synergy score of M = -10.
Calculate Final Score: Start with the Base Score (50) and add the component scores: $$C = 50 + E + M$$ $$C = 50 + 25 + (-10) = 65$$
Result: The final compatibility score is 65%. This indicates a strong initial attraction but requires conscious effort to manage the clash of two strong-willed, initiating personalities.

Frequently Asked Questions (FAQ)

How important is the sun sign in compatibility?: While the sun sign is important as it dictates ego and core personality, a full astrological compatibility reading (synastry) also considers the Moon (emotions), Mercury (communication), Venus (love), and Mars (action). The sun sign calculator is a strong starting point, but not the whole picture.
Do opposite signs (e.g., Aries and Libra) have good compatibility?: Opposite signs often have a high degree of compatibility (our formula scores them well). They represent two halves of a whole, offering balance and completing each other. They often share a common axis of experience but approach it from opposite directions.
Is same-sign compatibility always the highest?: Same-sign compatibility (e.g., two Tauruses) scores very highly in our formula (Elemental Affinity: +30) because of shared values and understanding. However, the identical Modality (e.g., Fixed-Fixed) can cause friction (-10), meaning that while they deeply understand each other, they may get stuck or resist compromise.
Why does the same modality reduce the score?: The same modality, particularly Cardinal (initiators) and Fixed (stubborn maintainers), implies a potential power struggle. For example, two Fixed signs may find it impossible to concede an argument, leading to gridlock. Different modalities generally facilitate flow and role division, which is why they are awarded positive synergy points.

Star Sign Compatibility Calculator