Astrological Compatibility Calculator

Explore your relationships!

Astrological Compatibility Calculator

by Psychic Science

Person A
Person B

Average Compatibility
(All selected)

Social Compatibility
(Ascendant - 'Rising Sign')

Temperament Compatibility
(Sun - 'Star Sign')

Emotional Compatibility

Intellectual Compatibility

Romantic Compatibility

Physical Compatibility

Ideological Compatibility

Long-Term Compatibility

About Astrological Compatibility

Astrological assessment of compatibility between two people is known as synastry. While there are different methods of synastry, astrologers agree that the most important indicators are the zodiac positions at birth of each person's Ascendant ('Rising Sign'), Sun ('Star Sign'), Moon, and faster-moving planets (Mercury, Venus, Mars, Jupiter and Saturn).

If you don't already have this astrological information you can get it using our FREE BIRTH CHART CALCULATOR.

What You Will Discover

Comparing birth chart signs with our free astrological compatibility calculator will assess different aspects of your relationships.

  • ASCENDANT signs indicate SOCIAL compatibility (how you get on socially).

  • SUN signs indicate TEMPERAMENT compatibility (how your natural personalities interact).

  • MOON signs indicate EMOTIONAL compatibility (how you relate emotionally).

  • MERCURY signs indicate INTELLECTUAL compatibility (how you communicate and share thoughts).

  • VENUS signs indicate ROMANTIC compatibility (how you relate romantically).

  • MARS signs indicate PHYSICAL compatibility (how you interact physically or sexually).

  • JUPITER signs indicate IDEOLOGICAL compatibility (how you react to each other's beliefs, values and opinions).

  • SATURN signs indicate LONG-TERM compatibility (how your relationship may develop and be sustained over time).

How to Use Our Compatibility Calculator

Simply select the relevant zodiac signs for each person's Ascendant ('Rising Sign'), Sun ('Star Sign'), Moon, and planets.

If you do not wish to use your real names, you can use initials or an alias - or just leave the Name fields blank.

Each area is given a percentage compatibility score and is graded either GREEN (good), AMBER (fair) or RED (poor).

You will also be shown each person's dominant characteristics in the various areas.

As you enter data, the results will be continually recalculated and updated. You do not need to enter all requested information, but the analysis will be more interesting and useful the more data you can provide.

How the compatibility scores are calculated

The scores obtained with this tool are calculated using special algorithms that take into account the relationship (similar and complementary) between the following astrological features in the two charts.

  1. Polarities (Positive vs Negative)

  2. Seasons (Spring, Summer, Autumn, Winter)

  3. Qualities (Cardinal, Fixed, Mutable)

  4. Elements (Fire, Earth, Air and Water)

  5. Signs (Aries, Taurus, Gemini, etc.)

The significance of each of these factors is also weighted, depending on its relevance to the type of compatibility being assessed (Social, Temperament, Emotional, etc.)

Polarities, Seasons, Qualities, and Elements


Zodiac Sign Polarities
Zodiac Polarities

In traditional astrology, each zodiac sign is considered either positive or negative, depending on whether its influence is largely active or passive (yang or yin). Polarity alternates through the 12 signs, beginning with Aries (positive) and ending with Pisces (negative).

  • Positive Signs (Active, Yang, Light) - Aries, Gemini, Leo, Libra, Sagittarius, Aquarius

  • Negative Signs (Passive, Yin, Dark) - Taurus, Cancer, Virgo, Scorpio, Capricorn, Pisces


Zodiac Sign Seasons
Zodiac Seasons

The Western Zodiac (also known as the Tropical Zodiac) is based on the annual seasons as these are experienced in the Northern Hemisphere.

Spring starts with the Spring Equinox, around the 20th March, and corresponds to the beginning of Aries.

Summer starts with the Summer Solstice, around the 21st June, and corresponds to the beginning of Cancer.

Spring starts with the Autumnal Equinox, around the 22nd September, and corresponds to the beginning of Libra.

Winter starts with the Winter Solstice, around the 21st December, and corresponds to the beginning of Capricorn.

  • Spring Signs - Aries, Taurus, Gemini

  • Summer Signs - Cancer, Leo, Virgo

  • Autumn Signs - Libra, Scorpio, Sagittarius

  • Winter Signs - Capricorn, Aquarius, Pisces


Zodiac Sign Qualities
Zodiac Qualities

Another traditional cyclical grouping of zodiac signs is based on how each contributes to the seasonal, developmental, or gestatory process. Three 'qualities' (or modalities) are traditionally recognised - Cardinal, Fixed, and Mutable. Cardinal signs are the creative initiators. Fixed signs provide a stable environment and foster maturation. Mutable signs shake things up and allow transformation to occur.

  • Cardinal Signs (Beginning, Impulse, Inception) - Aries, Cancer, Libra, Capricorn

  • Fixed Signs (Middle, Continuation, Stability ) - Taurus, Leo, Scorpio, Aquarius

  • Mutable Signs (End, Change, Movement) - Gemini, Virgo, Sagittarius, Pisces

Because each quality comprises four signs, these groupings are known in astrology as the Quadruplicities. Relationships between the three qualities are complex, and astrologers can have different opinions about which qualities are compatible.


Zodiac Sign Elements
Zodiac Elements

Each zodiac sign is also associated with one of the classical four elements (Fire, Earth, Air and Water). Again, these cycle through the zodiac, beginning with Aries (Fire) and ending with Pisces (Water).

  • Fire Signs (Energy) - Aries, Leo, Sagittarius

  • Earth Signs (Body) - Taurus, Virgo, Capricorn

  • Air Signs (Intellect) - Gemini, Libra, Aquarius

  • Water Signs (Emotions) - Cancer, Scorpio, Pisces

Because each element comprises three signs, the element groupings are known in astrology as the Triplicities.

Fire is traditionally considered to be opposed to Water (e.g., water puts out fire). Similarly, Earth and Air are opposites (e.g., body vs mind).

Relationships among the Zodiac Signs

Combining these various zodiac sign properties allow us to better understand the symbolic meanings of each sign and provides insight into the potential compatibilities and incompatibilities between the signs.

The Tropical Zodiac
The Tropical Zodiac
Zodiac Sign Classifications

Caution and Disclaimer

All astrological assessments made using this calculator, including compatibility scores and textual descriptors, are provided for entertainment purposes only. No claim is made concerning the accuracy of these assessments. By using this Compatibility Calculator you agree to accept any and all risks and liabilities that may result from its use.

Note that the calculated compatibility scores are not exact measurements, but rather approximate values. Further insight into the astrological dynamics and interpretation of a compatibility score may be obtained by considering the associated textual descriptors.

Finally, please bear in mind that human relationships are complex and, while it may be interesting and entertaining to explore astrological dimensions, they provide, at best, only a partial perspective. They should not be taken too seriously. Also, don't be surprised if they appear wide of the mark. If they seem inaccurate, they probably are. In these circumstances, it is much better to trust your own judgements about people and relationships.