Free Astrology Calculator
Stellium Calculator
Find out whether your birth chart has a stellium: three or more planets gathered in one sign or one house. Enter your birth details to see each group with exact degrees, what it emphasizes and where to read more.
What a Stellium Is
A stellium is a cluster of three or more planets in one zodiac sign or one house. When several planets share a sign, each of them (your identity, emotions, thinking, desires, drive) works through the same style, so that sign colors the chart far more than a single placement could. A house stellium does the same for an area of life. For a longer introduction, read what a stellium means in astrology.
How This Calculator Counts
- Three or more planets in the same sign or house make a stellium. Four or more is marked as a strong stellium.
- The ten planets count: Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. The North Node and Chiron count only if you tick them.
- No orb is required. Planets at 1 and 29 degrees of a sign still share it. The degree spread is shown so you can judge how tight each group is.
- Houses need your birth time and place. Placidus is the default; Whole Sign is available because many traditional astrologers prefer it.
Sign Stelliums and House Stelliums
A sign stellium describes temperament: how you act, feel and think. A house stellium describes where that energy is spent: career, home, relationships, work and so on. The two often overlap, but not always. A Scorpio stellium might sit in the 8th house, where it intensifies Scorpio themes, or spill across the 9th and 10th, where it brings Scorpio depth to study or career. Each of the twelve houses covers its own area of life; see the guide to house systems for how they are drawn.
If You Don't Know Your Birth Time
Tick "I don't know my birth time" and the calculator uses noon, then checks every sign each planet occupied during your birth date. Outer planets almost never change sign within a day, but the Moon does roughly every two and a half days, and Mercury, Venus and the Sun occasionally do. If a stellium depends on one of those, it is marked as possible rather than certain. Adding your birth place narrows the day to your local midnight-to-midnight.
How Accurate Is It?
Positions come from the same ephemeris that runs Selfgazer's planets today pages (VSOP87 planetary theory via Astronomy Engine), with Chiron from a Swiss Ephemeris table. Tested against the Swiss Ephemeris on random dates from 1900 to 2060, planets agree to within half an arcminute and house cusps to within a tenth of an arcminute. The local time is converted with your birthplace's historical time zone rules, including past daylight saving changes.
Stellium Questions
What Is a Stellium in Astrology?
A stellium is a group of three or more planets in the same zodiac sign or the same house of a birth chart. The sign or house holding the group becomes a major theme of the chart, because several different drives express themselves through it.
How Many Planets Make a Stellium?
This calculator uses the most common convention: three or more of the ten planets, Sun through Pluto. Some astrologers ask for four or more, so the results flag any group of four or more as a strong stellium.
Do the North Node and Chiron Count Toward a Stellium?
Most astrologers count planets only. The North Node is a calculated point and Chiron is a small body, so they are off by default. Turn them on if your teacher or tradition counts them, and the calculator will include them in the groupings.
Can I Find My Stellium Without a Birth Time?
Yes for sign stelliums, since most planets stay in one sign all day. The calculator checks every sign the Moon and faster planets could have occupied on your birth date and marks any stellium that depends on the exact time. House stelliums need the birth time and place.
Why Do Placidus and Whole Sign Give Different House Stelliums?
Placidus divides the sky by time, so houses have unequal sizes and can begin in the middle of a sign. Whole Sign makes each sign one house, starting with the rising sign. A group of planets can share one Whole Sign house while straddling a Placidus cusp, or the reverse.
Is a Stellium Rare?
Sign stelliums are fairly common. Mercury never strays more than about 28 degrees from the Sun and Venus never more than about 47 degrees, so the Sun, Mercury and Venus often share a sign. A stellium of four or more, or one built from slower planets, is less usual.
Can a Chart Have More Than One Stellium?
Yes. A chart can hold a stellium in two signs, or a sign stellium and a house stellium that overlap or point to different areas of life. The calculator lists every group it finds.