Birth Chart Basics
An orb is how far from exact an aspect can be and still count. There is no agreed set of numbers. A workable rule: give the Sun and Moon up to eight to ten degrees, other planets six, and minor...
Because an aspect is not a switch. A square at zero degrees from exact is overwhelming, at three degrees it is clear, at six it is present, and at nine it is arguable. Any cut-off is a convention drawn across a continuous slope, and different traditions draw it in different places.
Older practice assigned orbs to the planets rather than to the aspects, on the reasoning that a brighter body has a wider reach. That is why the Sun and Moon get more room in almost every system.
Use these until you have a reason not to. The one rule that genuinely matters is that an aspect within one or two degrees of exact does several times the work of one at the edge of its orb, and a chart reading that treats them equally will describe nobody in particular.
An aspect is applying if the faster planet is still moving toward exact, and separating if it has passed. Traditional practice treats applying aspects as much stronger, on the grounds that the event is still ahead rather than behind. Most modern software does not show you which is which, and it is worth working out for the tight aspects in your own chart.
| Aspect | Sun or Moon | Other planets | Notes |
|---|---|---|---|
| Conjunction | 8 to 10 degrees | 6 to 8 | The widest, because it is the strongest |
| Opposition | 8 to 10 degrees | 6 to 8 | Same as conjunction |
| Trine | 7 to 8 degrees | 5 to 6 | |
| Square | 7 to 8 degrees | 5 to 6 | |
| Sextile | 5 to 6 degrees | 3 to 4 | Weaker, so a tighter orb |
| Quincunx | 3 degrees | 2 to 3 | Minor, and often overclaimed |
| Semi-sextile | 2 degrees | 1 to 2 | Minor |
Two charts, both with Venus square Saturn. In the first, the aspect is 23 minutes from exact. In the second, it is five and a half degrees. The first person describes a lifelong and specific difficulty with affection and worth that colours everything. The second, asked about it, says it rings a faint bell.
That is the whole argument for orbs. The aspect is the same aspect, and the strength is not remotely the same.
aspect patterns, then how to read a birth chart, then Sun trine Moon.
Everything on this page is general by necessity. A reading built from your own date, time and place is the version that names your placements rather than describing the categories they fall into. If you do not know your birth time, this covers how to find it.
The allowance, in degrees, for an aspect to be away from exact and still count.
About eight for the Sun and Moon, six for other planets, two or three for minor aspects. Tighter is always stronger.
Less, and the drop-off is steep. An aspect within a degree does several times the work of one at six.
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