Free astrology tool
Zodiac Compatibility Checker
Select any two sun signs to see how their elements and modalities interact — with a compatibility score, elemental breakdown, and a link to the full pair guide.
Select two signs
How this calculator works
The compatibility score is based on two factors: elemental affinity (60% weight) and modal rhythm (40% weight). Element describes how two people fundamentally process experience — through action, sensation, thought, or feeling. Modality describes how they move through time — by initiating, sustaining, or adapting.
These two dimensions capture a meaningful amount of interpersonal dynamic between sun signs. The score is a useful starting point, not a verdict — real compatibility is more complex and is better understood through a full synastry chart reading.
Elements
Modalities
Frequently asked questions
How accurate is sun sign compatibility?
Sun sign compatibility is a useful starting point — it captures something real about elemental and modal dynamics between two people. However, it is only one layer of astrology. A full synastry reading compares every planet and angle in both charts, including Venus (love style), Mars (desire), Moon (emotional needs), and the Ascendant (first impressions). Sun sign compatibility gives you the broad brushstroke; synastry gives you the painting.
What is element compatibility in astrology?
The four astrological elements — Fire, Earth, Air, and Water — describe fundamentally different ways of engaging with life. Signs of the same element tend to feel immediately familiar. Fire and Air signs are traditionally compatible (action meets ideas), as are Earth and Water signs (practicality meets depth). Cross-element pairings are possible and even transformative, but they require more conscious navigation.
What is modality in astrology?
Modality (also called quality) describes how a sign operates within a season. Cardinal signs (Aries, Cancer, Libra, Capricorn) initiate. Fixed signs (Taurus, Leo, Scorpio, Aquarius) sustain. Mutable signs (Gemini, Virgo, Sagittarius, Pisces) adapt. Two signs of the same modality can create friction over who leads or who controls the pace.
Are opposite signs compatible?
Opposite signs — Aries/Libra, Taurus/Scorpio, Gemini/Sagittarius, Cancer/Capricorn, Leo/Aquarius, Virgo/Pisces — are complementary by design. They share the same axis in the zodiac and polarize around the same themes. Oppositions create tension but also attraction; many long-lasting couples are opposite signs.
What's the most compatible sign for each element?
Fire signs (Aries, Leo, Sagittarius) tend to be most compatible with Air signs and other Fire signs. Earth signs (Taurus, Virgo, Capricorn) tend to harmonize best with Water signs and other Earth signs. Air signs (Gemini, Libra, Aquarius) flow well with Fire and other Air signs. Water signs (Cancer, Scorpio, Pisces) connect deeply with Earth and other Water signs.