What an aspect configuration is
A single aspect is a relationship between two planets. A configuration is a closed group — three or more planets where every pairing within the group is itself in aspect, locking the shape into place. Because all the links close, the group behaves as one unit rather than a set of separate conversations, which is why astrologers read configurations as the dominant storylines of a chart.
The classic figures each have a signature geometry: a stellium is three or more planets packed into one sign; a grand trine is three planets mutually trining (an equilateral triangle within one element); a T-square is two planets in opposition both squaring a third; a grand cross is two oppositions at right angles; a yod is two sextiling planets both quincunxing an apex; and a mystic rectangle is two oppositions bridged by sextiles and trines.
The detector also matches six extended figures — the kite, the cradle, the minor grand trine, Thor's hammer, the golden yod and the grand sextile — several of which lean on minor-angle links (quintiles, sesquiquadrates, biquintiles) at tight 2° orbs. Each has its own dedicated page, linked below, with the exact geometry and worked charts.
How we detect them
Every planet's ecliptic longitude comes from sub-arcsecond astronomy (VSOP87/ELP via astronomy-engine). We classify each pair of planets by its nearest aspect using a fixed orb table — conjunction and opposition 8°, sextile, square and trine 6°, quincunx 3°, and for the minor-angle figures quintile 72°, sesquiquadrate 135° and biquintile 144° at 2°. The narrow minor bands sit clear of every major band, so adding them reclassifies no existing link.
Then we look for the closed combinations. Any sign holding three or more bodies is a stellium, and the aspect links between bodies are matched against each figure's exact multiset of connections.
Detection is fully deterministic: a figure is reported only when every link required by the shape falls within those published orbs, so the same chart always returns the same answer. For a T-square or yod we also mark the apex planet — the one that carries the figure's pressure — from the geometry rather than by eye.
What you get
After entering one birth date, time and place, the report lists every closed figure in your chart:
- Each configuration by name, with the planets involved and the signs/degrees they occupy.
- For stelliums, the sign and the tightness (the widest gap between neighbouring members).
- For T-squares and yods, the apex planet that discharges the figure's tension.
- A short, plain-English note on what each figure is traditionally held to mean.
How the figures are traditionally read
The broad principle is that harmonious closed shapes (grand trine, mystic rectangle) describe talent that flows easily — sometimes too easily, because a gift never called upon can lie dormant. Tense shapes (T-square, grand cross) describe friction that generates drive: the tradition treats them as the engine of achievement once consciously directed rather than repressed. A stellium concentrates a whole sign's temperament into one overpowering channel, and a yod marks an odd, 'fated-feeling' adjustment centred on its apex planet.
None of this is a measurement — it is one school's interpretive lens applied to real geometry. What is objectively true is that these patterns exist in the chart and that they cluster the chart's aspects into a handful of coherent storylines, which is why configuration-reading survives as a mainstream technique.
Two worked examples
A chart cast for 1 January 2000, 17:30 UTC in London contains a three-planet stellium in Aquarius: Neptune at 3.2°, Uranus at 14.8° and Mars at 28.1° of the sign. Even the widest gap between neighbouring members is only about 13°, so all three sit inside one sign and the tool reports it as a single Aquarius channel — here the chart's most concentrated statement, however you choose to read it.
The same chart also closes a T-square: the Moon at 16.1° Scorpio opposes Saturn at 10.4° Taurus (a wide 5.68° orb), and both square Uranus at 14.8° Aquarius — the Moon by 1.26°, Saturn by 4.43° — making Uranus the apex. It is the same Aquarius stellium member doubling as the pressure point, which is how configurations overlap in real charts.
A chart for 9 September 1975, 12:00 UTC shows a T-square spanning the cardinal signs: Jupiter at 23.6° Aries, Saturn at 29.2° Cancer and Uranus at 0.1° Scorpio. Jupiter and Uranus sit in opposition, and both square Saturn, which makes Saturn the apex — the point where the two opposing pulls focus. Each of those links falls inside our stated orbs, so the figure is reported.
Charts that contain none of these shapes are perfectly ordinary: their aspects simply remain a set of separate conversations rather than a few grand circuits.
What this tool does not claim
Orb choice decides which borderline figures appear. We publish a single consistent table (above) so detection is reproducible, but other astrologers use tighter or wider orbs, include the Part of Fortune or the angles in stelliums, or require a grand trine to stay within one element. A marginal T-square or a wide stellium may show here and not there, or vice versa — the geometry is identical, only the tolerance differs.
Configurations describe structure, not outcome; two people with the same figure live it very differently depending on the rest of the chart. And like natal astrology in general, the interpretive weight given to these shapes has no controlled support. All computation runs locally; your birth data never leaves your browser.
Where it sits next to other readings
Our Chart Patterns tool describes the chart's overall geometry — wheel shape, hemisphere and quadrant balance. This tool works the other way round: it stays inside the aspect web and names the specific closed figures, planet by planet. The Traditional Aspect list on the natal page shows every individual aspect so you can see the raw links these figures are built from.
Our method in one line
Planet longitudes from sub-arcsecond astronomy (VSOP87/ELP via astronomy-engine), pairs classified by nearest classical aspect on a fixed orb table, then closed combinations matched to each figure. Reviewed by Dr. Amara Osei, Astronomy Reviewer.
Step by step
- 1
Enter one birth record
Date, time and place — only the planetary positions matter here, so an uncertain birth time barely affects the result.
- 2
Scan the figures
Each closed shape is listed with its planets and degrees; read the apex note for T-squares and yods to see where the pressure lands.
- 3
Weigh the tone
Note whether your chart leans to flowing shapes (trines, rectangles) or driving ones (T-squares, crosses) — the classic easy-vs-effort axis.
- 4
Hold the orbs loosely
Tip: if a figure looks wide, treat it as suggestive rather than fixed; different authors would include or drop it. Tip: a chart with no closed figures is common and flexible, not broken.
Frequently asked questions
- What are the main aspect configurations?
- The six most commonly named are the stellium (three or more planets in one sign), the grand trine (three mutual trines), the T-square (an opposition squared by a third planet), the grand cross (two oppositions at right angles), the yod (two planets sextile each other and both quincunx a third), and the mystic rectangle (two oppositions bridged by sextiles and trines). Each is 'closed': every planet in the group aspects every other. Our detector additionally matches the kite, cradle, minor grand trine, Thor's hammer, golden yod and grand sextile, each covered by its own page.
- Is a stellium always exact, or can it be spread out?
- A stellium just needs three or more planets in the same sign; they do not have to be within a few degrees of each other. Our tool reports the widest gap between neighbouring members so you can see how tight it is. A very wide stellium (say 20°+ across the sign) is looser, and some authors would not count it — which is why we show the number instead of just a label.
- Are tense configurations like T-squares 'bad'?
- No. The tradition reads hard configurations as sources of motivation and accomplishment precisely because they create pressure that demands an outlet — many high achievers have prominent T-squares or grand crosses. Harmonious shapes are comfortable but can go unused. Neither is good or bad; they describe where a chart's energy is easy and where it has to be worked.
- Why does another site show a figure this one doesn't?
- Almost always orb differences. Aspect detection depends on how wide an allowed deviation (orb) you use and whether you restrict a grand trine to one element, include the angles, or count the quincunx. We publish our exact orbs so you can see why a borderline shape appeared or not; the underlying geometry never changes between sources.
- Is my birth data private?
- Calculations run entirely in your browser. Your birth data is never uploaded, never stored on a server, and never shared. Configurations are computed locally from your natal positions; nothing is uploaded or stored.
Written by
Elena Marchetti
Founder & Staff Astrologer
Methodology reviewed by
Dr. Amara Osei
Astronomy Reviewer
Published 2026-10-01 · Updated 2026-10-03 · Calculated with sub-arcsecond astronomy (VSOP87/ELP via astronomy-engine)