As per astrology, the degree of compatibility between two partners in a relationship is examined by comparing their star signs. While studying astrological compatibility, the natal horoscopes (birth charts) are examined for the personality traits. A person born at a specific time of the year is assigned with a particular star sign or zodiac sign. In total, there are twelve zodiac signs in astrology. According to astrology, it is believed that individuals born under a particular star sign express certain characteristics that are specific to that sign. Each zodiac sign, depending upon the time of birth, is assigned with an element. There are four elements, viz. fire, earth, air, and water. The Sun, the moon, and the nine planets are associated with at least one of the zodiac signs. At times, a star sign is ruled by two planets. Let's take a look at which star signs are compatible with each other. Aries (21 March - 20 April) Aries is the first sign of the zodiac. It is ruled by the planet Mars and fire is its element. Aries is best compatible with the star signs Leo and Sagittarius. People born under this sign also share good compatibility with Gemini, Aries, and Aquarius. But, they are least compatible with the Librans. Taurus (21 April - 21 May) Taurus sign is represented by the element Earth, while the planet Venus rules it. People born under Taurus make perfect partners with those of the Virgo and Capricorn. They also get along well with people born under Cancer and Pisces. But, Taurus people may have problems while having relationship with a Scorpion. Gemini (22 May - 21 June) The planet Mercury rules Gemini and its element sign is air. Gemini is best compatible with Libra and Aquarius, and to a lesser degree with Gemini, Aries, and Leo. According to astrological compatibility, a Gemini and Sagittarius may have lots of differences between them. Cancer (22 June - 22 July) The moon rules Cancer and its element sign is water. People born under the Cancer sign are best compatible with a Scorpion or a Piscean. They also make good partners with those having star signs Cancer, Taurus, and Virgo. The least compatible sign of Cancer is Capricorn. Leo (23 July - 22 August) The Sun rules Leo and fire is the element for this sign. A relationship between Leo and Aries or Leo and Sagittarius would make a perfect match. However, a Leo also shares good compatibility level with those born under Leo, Gemini, and Libra signs. Usually, Leo people face relationship problems with the Aquarians. Virgo (23 August - 21 September) The element Earth represents Virgo sign and Mercury is its ruling planet. Virgo is best compatible with Cancer and Scorpio. People born under this sign also make near perfect partners with those born under the Virgo, Cancer, and Scorpio signs. Virgo sign is least compatible with Pisces. Libra (22 September - 22 October) Libra is represented by the element air and the planet Venus rules this sign. It is believed that Librans are perfect partners for Aquarians and Gemini people. Also, Libra is compatible with Leo, Sagittarius, and its own star sign Libra. Nonetheless, a Libran should think twice before tying knot with an Arian. Scorpio (23 October - 21 November) The element sign for Scorpio is water; whereas, its ruling planets are Mars and Pluto. Scorpio makes perfect partners with Cancer and Pisces, and is also compatible with fellow Scorpio, Virgo, and Capricorn. A successful relationship between a Scorpion and Taurus is doubtful. Sagittarius (22 November - 21 December) The planet Jupiter rules Sagittarius sign and fire is the element of this zodiac sign. The best compatible signs for Sagittarius are Aries and Leo. They also get along with fellow Sagittarius, Libra, and Aquarius. The least compatible star sign for Sagittarius is Gemini. Capricorn (22 December - 20 January) Capricorn sign is represented by the element earth and Saturn is its ruling planet. Capricorn makes perfect partners with the star signs Taurus and Virgo; however, fellow Capricorn, Scorpio and Pisces are also good compatible signs. The worst match for a Capricorn is Gemini. Aquarius (21 January - 19 February) The planets Saturn and Uranus rule Aquarius sign, while the element for this sign is air. Aquarius makes best partners with Gemini and Libra. People born under Aquarius will also have good relationships with fellow Aquarius, Aries, and Sagittarius. On the contrary, Leo sign is not compatible with Aquarius. Pisces (20 February - 20 March) The Pisces sign is ruled by two planets, viz. Jupiter and Neptune. Its element sign is water. Pisces sign makes a perfect match with the star signs Cancer and Scorpio. The compatible partners also include Pisces, Taurus, and Capricorn. The least compatible zodiac sign of Pisces is Virgo. Well! It is up to the individual whether to believe or not in astrological compatibility. To be practical, it is not horoscope and astrology that make a relationship work. A wonderful relationship is all about love, understanding, and loyalty between the partners.