Zodiac Compatibility Calculator

Zodiac Compatibility Calculator

What this calculator does

Western astrology assigns everyone a "sun sign" based on the position of the sun on their birth date - one of the twelve familiar signs from Aries to Pisces. Each sign also belongs to one of four elements: Fire, Earth, Air, or Water. This calculator uses your birth date and a partner's birth date to compute:

• your sun sign and element
• your partner's sun sign and element
• a compatibility score and label based on how your elements interact
• a checklist of personality traits for both signs, and which relationship (same sign, same element, complementary elements, or challenging elements) applies

Formula used

Sun sign is determined by matching your birth month and day against the twelve traditional date ranges (for example, Aries runs March 21 - April 19, Taurus runs April 20 - May 20, and so on through the calendar year).

Element is fixed per sign - three signs share each element:

• Fire: Aries, Leo, Sagittarius
• Earth: Taurus, Virgo, Capricorn
• Air: Gemini, Libra, Aquarius
• Water: Cancer, Scorpio, Pisces

Compatibility between your sign and your partner's is determined, in order of priority:

1. Same sign - identical sun sign. A strong match (95%).
2. Same element - different signs, same element (e.g. Aries and Leo, both Fire). An excellent match (88%), since you share a natural rhythm.
3. Complementary elements - Fire with Air, or Earth with Water. A great match (85%): Air feeds Fire, and Water nourishes Earth.
4. Challenging elements - any other pairing (Fire with Earth or Water, Air with Earth or Water). A more challenging match (50-55%) that typically needs extra communication.

$$score = \begin{cases} 95 & \text{same sign} \\ 88 & \text{same element} \\ 85 & \text{complementary elements} \\ 50\text{-}55 & \text{challenging elements} \end{cases}$$

How to use it

1. Enter your birth date.
2. Enter your partner's birth date.
3. Submit to see both sun signs, the compatibility score, a summary explaining why, and a checklist of traits for each of you.

Example

Someone born on June 15 falls between May 21 and June 20, so they are a Gemini (Air element).

Their partner, born on September 10, falls between August 23 and September 22, so they are a Virgo (Earth element).

Gemini is Air and Virgo is Earth - not the same sign, not the same element, and not one of the Fire/Air or Earth/Water complementary pairs - so this pairing lands in the challenging category, scoring around 55%, and the summary explains that the two elements tend to pull in different directions.