✷ Free Stellium Calculator — Do You Have One?
Umbriel's free stellium calculator shows every cluster of planets in a single sign and in a single house in your birth chart, with exact degrees. No account, no email. There is no agreed definition of a stellium — three planets or four, by sign or by house — so Umbriel shows you the groupings and lets you apply whichever rule you were taught.
- What you'll needBirth date, time and place
- What you getEvery cluster of planets in one sign and in one house, with the exact degrees, so you can see how tight each grouping really is
- CostFree — no account required
Runs in your browser. Nothing to install, nothing to set up.
What a stellium actually is
A stellium is a stack of planets bunched into one sign or one house, read as a concentration of emphasis: a lot of the chart's attention pointing at one place. That much is agreed. Almost nothing else about it is.
⚠️ Some astrologers require three planets, some insist on four. Some count only the traditional seven; others include Uranus, Neptune, Pluto, the Ascendant, the Midheaven, Chiron or the nodes, which changes the answer for a great many charts. Some count by sign, some by house, and the two rarely agree — a group spread across a sign boundary can be a house stellium and not a sign one, and vice versa. A calculator that just announces "you have a stellium" has quietly picked one of these rulebooks without telling you.
So the useful question is not whether you have one but how tight the grouping is. Three planets spread across twenty-five degrees of a sign behave very differently from three sitting within four degrees of each other, where they are also conjunct and read as a single fused voice. Umbriel gives you the degrees and the conjunctions, which is the information the label is standing in for.
What's in your result
- Every group by signAll the signs holding three or more bodies, with what is in each.
- Every group by houseThe same for houses, which often disagrees with the sign grouping. Needs your birth time.
- The exact spreadHow many degrees the cluster covers — the difference between a tight fused group and a loose one.
- Whether they are actually conjunctA tight stellium is also a set of conjunctions, and Umbriel lists them with their orbs.
- Which bodies are includedNamed explicitly, so you can re-count under whatever rule you were taught.
- The sign's rulerWhere the ruler of a stellium's sign sits — traditionally the placement the whole cluster reports to.
Common questions
How many planets make a stellium?
There is no settled answer. Three is the most common threshold and four is the stricter one, and both are defensible because the word has no formal definition. Umbriel shows the groupings and their sizes rather than picking a rule on your behalf.
Does a stellium count by sign or by house?
Both are in use, and they often disagree — a cluster straddling a sign boundary can be a house stellium without being a sign one. Umbriel calculates both so you can see which kind you have.
Do the outer planets count in a stellium?
That depends who taught you. Traditional astrology works with the seven visible bodies, so a group of Uranus, Neptune and Pluto would not have counted at all; modern astrology usually includes them. Since the outer planets move slowly, including them means whole birth-year cohorts share the same stellium, which is worth knowing before reading much into it.
What does having a stellium mean?
It is generally read as concentrated emphasis — a large share of the chart pointing at one sign or one area of life. It is a matter of degree rather than a special status, and the tightness of the grouping usually matters more than the count.
Is the stellium calculator free?
Yes — every grouping by sign and by house, with degrees and conjunctions, and no account or email.
Go deeper
Every one of these is a page in its own right, written out one at a time.
Related free tools
Umbriel offers every system here as a set of prompts to think with, never as a statement of fact about who you are. Take what's useful, leave the rest.