From the time you first learned to read your horoscope, chances are you turned to astrological compatibility readings to understand how you'd fare with your crush. And these days, it's more like how you'll connect with that hot match on Bumble or even your long-term love. But looking at how two signs connect and clash can be useful for an array of relationships, from your friendships to your siblings to your colleagues. And if you're always finding yourself working on professional projects with Cancers or hitting it off right away with Aquarians, it's possible you're making the most of your astrological sister sign.
Here, the basics on sister signs, aka astrology's polar opposites or polarities.
If you have an actual sibling, you know that you share some traits — your laughs, your eyes, your love of '90s teen soaps — but perhaps you're polar opposites when it comes to other characteristics. Your sister is a total workaholic, and you're a free spirit. Your brother's a homebody, and you're a globe-trotter. In astrology, sister signs function in this same way.
Located six signs or 180 degrees away from one another on an astrological wheel and rulers of opposing houses — say, the first and the seventh (that's you, Aries and Libras) or the fifth and the eleventh (Leo and Aquarius) — sister signs share the same quality (aka quadruplicities):
Cardinal: These signs are the big-picture thinkers of the zodiac, excelling at brainstorming and initiating, but they struggle with follow-through. They include Aries (fire), Cancer (water), Libra (air), and Capricorn (earth).
Mutable: These signs are the most adaptable of the zodiac, but they can also be indecisive and flighty. They include Gemini (air), Virgo (earth), Sagittarius (fire), and Pisces (water).
Fixed: These signs dig their heels in, for better (say, being up for doing the work in a long-term relationship) or worse (refusing to change their career path, even if it's making them sick). They include Taurus (earth), Leo (fire), Scorpio (water), and Aquarius (air).
And you likely already know that there are four elements: Fire, Earth, Air, and Water. Well, they're also divided up into what's referred to as dualities. Fire and Air are the "active" elements, which are more assertive, energetic, and well, action-oriented, while Earth and Water are "receptive," aka they generally prefer to tune into their emotions and intuition before making their move. Sister signs are always the same duality.
Working to understand your astrological opposite, or sister sign, can help you pinpoint qualities you might be lacking that you could learn from people in your life who possess them, thanks to their astrological placements in that sign. Although we often associate "opposite" with opposition or tension, the word has a much more nuanced application in astrology.
Sure, any opposition can be frustrating, challenging, or even lead to a lot of eye-rolling, huffing, and wanting to pull your hair out (just like the worst fight you ever had with a sibling or BFF). But if you're up for playing ball with it, an opposition can also lay the foundation for intensely satisfying inner work, common ground, and balance. In other words, people you meet who have a lot of your sister sign in their birth charts could be the ultimate yin to your yang. (See: Everything to Know About Zodiac Compatibility)
Check out the sister sign that pairs with your sun or rising sign. Then consider your moon and possibly even all of your big six (meaning, your sun, moon, rising, Mercury, Mars, and Venus). It could be that you often connect with people who have the sister sign to your rising sign (as that'll be the sign that rules your seventh house of partnership) or natal Venus (the planet of relationships).
The Sister Signs for Each Zodiac Sign:
♈️ Aries' sister sign is Libra.
♉️ Taurus' sister sign is Scorpio.
♊️ Gemini's sister sign is Sagittarius.
♋️ Cancer's sister sign is Capricorn.
♌️ Leo's sister sign is Aquarius.
♍️ Virgo's sister sign is Pisces.
♎️ Libra's sister sign is Aries.
♏️ Scorpio's sister sign is Taurus.
♐️ Sagittarius's sister sign is Gemini.
♑️ Capricorn's sister sign is Cancer.
♒️ Aquarius's sister sign is Leo.
♓️ Pisces' sister sign is Virgo.
Aries and Libra
Polar opposites: Aries, the cardinal fire sign and the ruler of the First House of Self, faces off against Libra, the cardinal air sign and ruler of the Seventh House of Partnership. Although both are go-getters, Aries is ruled by Mars, the planet of action and aggression, while Libra is a peacemaker first and foremost, ruled by Venus, the planet of love. Aries will literally ask people to fight with them for fun, while Libra will avoid conflict at all costs, even to the point that they get passive-aggressive or ill.
Perfect pair: As initiating cardinal signs, these two are equally psyched to kick off large-scale, sweeping projects. Impulsive, fiery Aries can challenge indecisive, airy Libra to move more quickly to a decision as well as to stand in their sense of self. Libra can help soften Aries' blustery approach, teaching them how diplomacy and killing your opponent with kindness can often be just as — or even more — effective than handling a conflict like a bat out of hell.
Taurus and Scorpio
Polar opposites: Taurus, the fixed earth sign and ruler of the Second House of Money, opposes Scorpio, the fixed water sign and ruler of the Eighth House of Sex and Death. Ruled by pleasure-first Venus, Bull people basically come in second after Libra for most conflict-averse of the signs, preferring to chill out, soak up beautiful art and sumptuous food, and take it easy. Meanwhile, Scorpio, co-ruled by aggressive Mars and transformative Pluto, is intense about everything, wanting to live their best life in a bolder, more take-charge way. As (eerily) silent as they might outwardly appear, Scorpios have zero chill.
Perfect pair: Taureans are often labeled the most stubborn sign of the zodiac, but the truth is that all of the fixed signs are, and both the Bull and the Scorpion are wired to take a stand — and refuse to back down. That's why they're often a match made in heaven for any kind of long-term relationship, whether romantic, platonic, or professional; they both tend to fully commit to making things work, and see eye-to-eye on that intensity. (Both are super-sensual, though, so if the bond is a love or sex-based one, expect lots of sparks.) Taurus can help Scorpio embrace the calmer, more grounded side of life, while Scorpio can help Taurus get comfier wading into the depths of emotion and passion.
Gemini and Sagittarius
Polar opposites: Gemini, the mutable air sign and ruler of the Third House of Communication, sits across from Sagittarius, the mutable fire sign and ruler of the Ninth House of Higher Learning and Adventure. Ruled by messenger Mercury, Gemini is constantly soaking up and disseminating information in a curious, often lighthearted way. Think of the Twins as the chatty, wide-eyed little kids of the zodiac; they're not ones to take themselves super seriously. But Sag, on the other hand, is ruled by expansive Jupiter, obsessed with knowledge in a far more professorial, know-it-all way that can come off as soapbox-y. Unfiltered and passionate, they're full of opinions and fervent beliefs.
Perfect pair: Although they might express themselves and function in social settings very differently, both Gemini and Sag are hungry for information, connection, and eye-opening experiences. They're the two most wanderlust-filled signs in the zodiac and would absolutely love to go on an adventure together, be it global or local. Gemini can encourage Sag to consider a variety of opinions, while Sag can nudge Gemini to adopt a deeper, more philosophical perspective. (See: How to Tune Into Astrocartography, the Astrology of Travel)
Cancer and Capricorn
Polar opposites: Cancer, the cardinal water sign and ruler of the Fourth House of Home Life, opposes Capricorn, the cardinal earth sign and ruler of the Tenth House of Career and Public Image. Ruled by the intuitive, heartfelt moon, emotional Cancer can't help but nurture others, prioritizing family, their domestic sanctuary, and a sense of inner security. On the flipside, Cap, ruled by industrious taskmaster Saturn and symbolized by the Sea Goat, is determined to climb their way up their own personal mountain to achieve recognition, rewards, and respect. This isn't to say they're not also family-oriented, as old-school Saturn offers a love of tradition, but they're first and foremost driven to cultivate an applause-worthy professional rep.
Perfect pair: While we, as a society, tend to pit home life against work life, the fact is that you're likely to function best and be most successful in both areas when there's symbiosis. Cancer and Cap are a clear example of how those two seemingly opposing energies not only can but must work together. Cancer shows Capricorn how to celebrate the joys of home, simply bonding with loved ones, and caring for your emotional core, while Capricorn teaches Cancer the pleasures of being recognized professionally and how to use a pragmatic, steady approach to get concrete results. Ultimately, these two have more in common than meets the eye, as they share a mutual desire to build something that's lasting and fulfilling.
Leo and Aquarius
Polar opposites: Leo, the fixed fire sign and ruler of the Fifth House of Romance and Self-Expression, sits across from Aquarius, the fixed air sign and ruler of the Eleventh House of Networking and Long-Term Wishes. Ruled by the buoyant sun, self-assured Leo wants to be in the spotlight, have fun, dance, own and use their fierce roar, flirt, fall madly in love, have lots of fireworks-inducing sex… basically be an '80s pop star. But future-minded, team player Aquarius, whose modern ruler is rebellious Uranus and whose traditional ruler was taskmaster Saturn, is an intellectual idealist focused on what's best for the collective versus the self. Free-spirited, rational, and eager to strike out against convention, they're most likely to step into the limelight when they're marching for a social cause alongside friends or colleagues.
Perfect pair: Leo's focus on self and tendency to be loud and proud will 100 percent clash with Aquarius' cool, stoic front and devotion to community. But working together, they'll realize they need one another's skills and perspectives. In fact, as two fixed (aka stubborn) signs who believe their way is the best way, they're a lot more alike than they might initially guess. Leo can teach Aquarius how to promote and brand themselves for the sake of their humanitarian campaigns, while Aquarius can help Leo see outside of their glitzy, glimmering bubble and use their roar for purposes that benefit communal causes that are close to their hearts.
Virgo and Pisces
Polar opposites: Virgo, the mutable earth sign and ruler of the Sixth House of Health and Daily Routine, opposes Pisces, the mutable water sign and ruler of the Twelfth House of Spirituality. Ruled by researcher Mercury, practical, analytical Virgo is all about facts, figures, lists, spreadsheets, and details that come complete with footnotes. And they're downright gleeful when they can use their info-gathering skills to be of service to their nearest and dearest or colleagues. The Fish, by comparison, is ruled by Neptune, the planet of dreams that tends to cloud rational thought. Deeply feeling and slightly psychic, they're wired to let their emotions, intuition, and imagination take the reins over logic.
Perfect pair: Tending to the minutiae of daily life and your health and well-being might sound like a snoozefest, but Virgos know there can be not only order but also magic in it. Getting your ducks in a row can create space for play and poetry, and that's exactly what Virgo can impart to Pisces. And Pisces can help Virgo get out of their head and into their heart and spirit, learning to trust themselves to go swimming in the deep end of their most complicated, confusing feelings. Ultimately, both the Fish and the Maiden could realize they're one in the same as empaths who aim to use their strengths to heal others.
Maressa Brown is a writer and astrologer with more than 15 years of experience. In addition to being Shape's resident astrologer, she contributes to InStyle, Parents, Astrology.com and more. Follow her Instagram and Twitter at @MaressaSylvie.