What aspects are
Every planet in your birth chart sits at a point on the zodiac, and the angles between them are the aspects. Astrologers read the planets as what is talking, the signs and houses as where and how, and the aspects as the conversations between them. Only certain angles count: those that divide the circle evenly, which astrologers have used since antiquity. An aspect doesn't need to be exact; each is allowed an orb, a few degrees either side, and the closer to exact, the stronger it is read.
The calculator above draws them as a grid, one row and column for each planet (and for the Ascendant and Midheaven with a birth time), so every pair appears once. It then looks for the shapes that three or four planets can make together, the aspect patterns, which astrologers read as the chart's big structures.
The All major aspects list gives the pairs in words, with both zodiac positions and their orbs. Filter by a point, an aspect or a pair of points; either order of a pair finds the same connection. Use Show more aspects to read the full list, or print every matching result.
How common each pattern is
| Pattern | Planets | Share of charts |
|---|---|---|
| T-square | 3 | 53% |
| Yod | 3 | 17% |
| Grand trine (outside a kite) | 3 | 11% |
| Kite | 4 | 10% |
| Mystic rectangle | 4 | 6% |
| Grand cross | 4 | 5% |
Measured on 3,000 random birth charts from 1950 to 2009, with birth times, using the calculator's own orbs. About 3 charts in 10 had none of them, so a chart without a named pattern is ordinary. A pattern made only of Jupiter and the slower planets is shared by everyone born within weeks or months, and the calculator marks those as generational. The stellium, three or more planets crowded into one sign or house, is the other pattern astrologers name, and has its own calculator.
Reading a pattern
Start with the planets in it: a T-square with the Moon at its apex is read quite differently from one with Saturn there. Then the signs: a grand trine all in water signs, or a T-square all in fixed signs, is read as that element's or modality's theme, turned up. Last, the orbs: the tighter the pattern, the louder it is read. The calculator names the element of a grand trine, and the modality of a T-square or grand cross, when all its planets share one, and it gives the widest orb in each pattern.
Aspects between two charts
The same aspects are read between two people's charts, where they describe how two lives meet rather than how one is built. The synastry chart lists them for any two birth charts, and the birth chart draws your own aspects on the wheel.
How it is worked out
The planets and angles come from the site's own ephemeris, the same one behind every chart here. Aspects are measured along the zodiac with the birth chart's orbs, listed in the questions above. Without a birth time, the Moon, which moves about 13° a day, and the Ascendant and Midheaven are left out, so fewer patterns can be found. Your details stay in your browser.