Why Some Astrologers Don’t Believe In Zodiac Cusps

If you've ever told an astrology lover that you don't really identify with your sun sign, they may have asked you if you're a cusp. Meaning: Were you born right on or near the day when the sun moves from one sign to the next? Some people think that being a cusp means you could take on the traits of the adjacent sign as well as your own.

Take Jenna, for example. Her birthday falls right on January 20, the date that the sun moves into idealistic and independent Aquarius from pragmatic and disciplined Capricorn. "When I was younger I totally identified as an Aquarius, but as I got older I identified more with being a Capricorn," the 24-year-old tells Refinery29. "Now, I just tell people I'm a cusp baby, and buy both signs in mugs and things."

Jenna's reasoning makes sense — you're born close to two signs, so you embody characteristics of both. According to astrologers, though, that isn't exactly how the zodiac works. "In astrology, there's no such thing as cusp signs," Maren Altman, an astrologer based in New York, tells Refinery29. "You can be on the cusp of a sign, but that does not mean that you inherit traits due to a blending of the signs."

Leslie Hale, psychic astrologer for Keen.com, agrees, saying: "The fact is the sun, or any other planet, can only be in one place at any given time. You are the sign you were born under." Sorry Jenna: You're a Capricorn. (Well, not sorry, actually — Caps are kind of the best.)

In Western astrology, the sky is equally divided into 12 equal parts, which form the 12 signs of the zodiac. "The term 'sun signs' comes from the sun presently being in one of the 12 zodiac signs," explains Narayana Montúfar, senior astrologer for Astrology.com. "Even if someone was born on the day that the sun moved from one sign to the next, their sun sign will be determined by where the sun physically was at their exact moment of birth." And apparently, there's no such thing as the sun being "on the line" or half in one sign, half in another at the time of your birth.

The idea of cusps didn't become a phenomenon until the relatively recently, Altman says. She links it back to the explosion of interest in astrology that stared in the 2010s. People started checking their daily horoscope via apps, sites, and (if they were really old school) newspapers — but they were only reading about their sun signs, which is just one small part of your astrological makeup. "The confusion usually stems from not understanding that astrology is not based on one sign, it's based on the entire map of the sky at your time of birth," she explains. We have entire natal charts filled with planets, signs, and aspects that all help us figure out who we really are.

For example, Montúfar points to the placement of Mercury in our charts as why those born just on the edge of a certain sign may feel the pull of another sign's energy, like Jenna. "Being the very next planet from the sun, Mercury is never far from it," Montúfar explains. "If you’re a Scorpio sun, your natal Mercury has to be either in Libra, Scorpio, or Sagittarius. In the case that your sun sign is Scorpio and your Mercury is in Sagittarius, sure, you can easily attribute the strength of your Mercury to your sun 'being on the cusp.'"

We asked for Jenna's birth chart to figure out exactly where her Aquarian energy was coming from. Turns out, out she's not just a Capricorn sun — she a Capricorn moon, rising, and Mercury as well. But she does have two planets in Aquarius: Mars and Uranus. Mars is the Planet of Aggression, and it peeks out in how you assert yourself (and in your sex life). Jenna might feel connected to her inner water bearer during moments of passion. Uranus, on the other hand, shows up in how you rebel; if the planet resides in Aquarius, you may be more concerned with humanitarian causes. Jenna says she still thinks of herself as a cusp, because she feels like an Aquarius in some ways — but knowing what she knows about her birth chart, when people ask her sign, she'll start saying Capricorn.

Astrologer Lisa Stardust points to her best friend as another example of someone whose cusp-ish ways make sense once you take a look at their whole birth chart. "My BFF since I was three years old is a Cancer sun sign, and she was born the day the sun moved into Cancer," she explains. "But, she has a few planets in Gemini, and takes on that energy naturally in her chart." This sort of thing can work for non-cuspers too. My boyfriend's Cancer sun always threw me off (he's not really all that outwardly emotional) but once I learned he had a Scorpio moon and a Scorpio rising, his personality fell into place.

If the realization that cusps aren't real is giving you a minor identity crisis, plug your birth info into a natal chart generator, such as the one on Astro.com or CafeAstrology.com. Understanding where the planets were when you were born will open a new window into understanding why you feel Leo-ish in some ways, Virgo-y in others. And you can still buy the zodiac mug you most identify with, whether it's printed with your rising sign, your moon sign, or something else entirely. Astrology is meant to be fun, after all.