How Your Zodiac Sign Affects Romantic Compatibility—Learn How You’ll Connect or Clash!

One of the reasons you’re undoubtedly head over heels for learning about astrology is how much the 2,000+-year-old practice can teach you not only about yourself but your loved ones. For example, if you were born with slow and steady Taurus placements, you might experience crossed wires with a partner who has significant fast and fiery Aries in their birth chart. But simply being more aware that you each have your own unique perspectives and M.O.s can make for even slightly smoother sailing. 

That said, there’s so much more to compatibility than considering two sun signs (a.k.a. the sign that the sun was moving through when you were born). In fact, we professional astrologers often use an area of astrology called synastry to compare two birth charts and identify points of harmony and tension for a couple. But by learning a few basics, you can better understand what to look for when it comes to zodiac sign compatibility. If you’re curious about the romantic compatibility rules of the road in astrology, here’s what you’ll need to know in order to get a sense of how you’ll connect or clash with a significant other or potential partner.

Planetary placements to zero in on for romantic compatibility

Because your sun sign colors your self-image, confidence, purpose, self-esteem and identity, there is definitely merit to taking your sun sign and a partner’s into account when thinking about compatibility. But it’s really just the tip of the iceberg. You’ll also want to think about the following planets and angles in each of your birth, or natal, charts:

The moon

I like to call the moon your astrological “emotional compass,” as it shapes your inner world, emotional nature and needs, intuition and instincts, sense of security, your values and how you nurture as well as how you want to be nurtured. Because all of these characteristics are heavily involved in how you’ll connect with someone romantically, the moon is a key player in romantic compatibility. 

Venus

The planet of romance and relationships, Venus influences how you express yourself creatively, perceive beauty, earn money, experience pleasure and demonstrate affection. It’s the planet that informs your love language, which is why it’s so integral to love compatibility. (Personal side note: I feel very fortunate to say that I’ve experienced firsthand how helpful it can be to have a significant other who shares the same Venus sign. It means we’re more likely to see eye-to-eye on not only what we find romantic, attractive and pleasurable but how to spend money. Though you don’t necessarily have to have the same Venus sign as your partner to see this kind of benefit. More on that in a moment.)

Mars

The planet of action, energy and sex, Mars powers how you pursue your goals, get fired up and passionate about just about anything, experience and express anger as well as inner drive and sex drive and assert yourself — themes can’t help but come up when you’re navigating a romantic relationship.  

Mercury

The planet of communication isn’t classically thought of as a planet to home in on when thinking about romance in astrology, but it is still worth taking into consideration, because it informs your communication style, approach to information-gathering and sharing, thought processes, decision making and how you learn. And of course disconnects in these areas could lead to misunderstandings and friction for a couple.  

Planetary connections to look for

Once you’ve identified both your own and your partner’s sun, moon, Venus, Mars and Mercury signs, you’ll do well to think about how they’re interacting with one another. Aspects in astrology, or the angles that two planetary placements are making to one another, can tell you a lot about how easygoing or challenging a connection will be. Pro-tip: Look for connections among all of these placements, not just Venus to Venus or Mercury to Mercury.

Conjunction

Say your partner’s Mars is in Cancer, and your Venus is also in the sentimental cardinal water sign. This is called a conjunction. (If you can identify the degrees of each placement, even better, because you can see just how closely conjunct they are. Within 10 degrees of one another is ideal.) Because you share a sign’s energy — even if it happens to be across two different planetary placements, such as Mars and Venus — it’s easier to get in sync. Conjunctions promote mutual understanding and commonalities. 

Trine

If your partner has a romantic placement that’s in the same element (fire, earth, air and water) as your own, they form a 120-degree angle known as a trine. In astrology, a trine creates a free-flowing, positive aspect that spurs easygoing energy. An example: Your moon is in Virgo, and your partner’s Mercury is in fellow earth sign Capricorn. The way in which you experience emotion and nurture (the moon) is naturally harmonious with your partner’s communication style (Mercury).

These are the signs that trine one another:

Fire: Aries, Leo, Sagittarius

Earth: Taurus, Virgo, Capricorn

Air: Gemini, Libra, Aquarius

Water: Cancer, Scorpio, Pisces

Sextile

Sextiles occur between placements that are 60 degrees apart and fall in elements that are classically simpatico with one another. Fire signs sextile air signs, and water signs sextile earth signs. That said, if your partner’s Mars is in social air sign Libra and your moon is jovial fire sign Sagittarius, the way your S.O. takes action and expresses their sex drive will be compatible with your instincts and emotional nature. 

These are the signs that sextile one another:

Aries: Gemini, Aquarius  

Taurus: Cancer, Pisces

Gemini: Aries, Leo

Cancer: Taurus, Virgo 

Leo: Gemini, Libra 

Virgo: Cancer, Scorpio 

Libra: Leo, Sagittarius 

Scorpio: Virgo, Capricorn 

Sagittarius: Libra, Aquarius 

Capricorn: Scorpio, Pisces 

Aquarius: Aries, Sagittarius 

Pisces: Taurus, Capricorn

Opposition

In astrology, an opposition occurs when two planets or luminaries (the Sun or moon) sit directly across from one another in opposing signs. Oppositions happen in signs that share the same modality (cardinal, fixed or mutable) but fall under different elements (fire, earth, air and water). If you and your S.O. have romantic placements that oppose one another, you could feel as though you’re two sides of the same coin and balance one another out — or like you’re speaking two totally different languages.

These are the signs that oppose one another:

Aries-Libra

Taurus-Scorpio

Gemini-Sagittarius

Cancer-Capricorn

Leo-Aquarius

Virgo-Pisces

Square

Considered the most tense but also activating aspect in astrology, a square is when two planets connect from a 90-degree angle. Squares occur between planets (or luminaries, which include the sun and the moon) in signs that share the same quality (cardinal, fixed or mutable) but fall under a different element (fire, earth, air and water). So if your Venus is in Leo, and your partner’s moon is in Scorpio, you might experience a great deal of passion but also head-butting, because both of these signs are fixed and therefore struggle with obstinacy.

These are the signs that square one another:

Aries: Cancer and Capricorn

Taurus: Leo and Aquarius 

Gemini: Virgo and Pisces 

Cancer: Aries and Libra 

Leo: Taurus and Scorpio

Virgo: Gemini and Sagittarius

Libra: Cancer and Capricorn

Scorpio: Leo and Aquarius

Sagittarius: Virgo and Pisces

Capricorn: Aries and Libra

Aquarius: Taurus and Scorpio

Pisces: Gemini and Sagittarius

How to further explore romantic astrological compatibility 

Comparing your chart and romantic planetary placements to your partner’s is a fantastic jumping off point for getting a keen sense of your strengths and setbacks as a pair. But because astrology is so multilayered and nuanced, chances are there’s even more going on between you and your S.O. than might initially meet the eye. 

For example, learning more about and checking out how placements are dispersed among the houses can also offer insight into how you might click or not. That’s because some houses emphasize privacy, even secrecy, while others are much more open and forthcoming. So, if one person has several placements in, say, the Twelfth House of Spirituality or Eighth House of Intimacy (a couple of those reserved ones) and the other has quite a bit in their First House of Self or Tenth House of Public Image (more outgoing zones), you might have very different ways of being in the world that aren’t necessarily incompatible but might require extra work in order to bridge the gap. 

The bottom line: A quick glimpse at two birth charts makes it clear that you and your partner both contain multitudes and astrological compatibility is complex, nuanced — and far less straightforward than internet memes would have you believe. Exploring your connections and challenges can bolster mutual understanding, and should you want to go a bit further and do a deep dive on your synastry, you’ll always benefit from working one-on-one with a pro astrologer.