Birth-chart structure
Astrological Aspects
Aspects describe angular relationships between planets or chart points. They are one of the main ways astrologers interpret how separate parts of a chart interact.
Reviewed and updated: August 31, 2026
The five major aspects
| Aspect | Exact angle | Traditional reading |
|---|---|---|
| Conjunction | 0° | Two factors combine or intensify one another. |
| Sextile | 60° | Opportunity, cooperation or an easier connection. |
| Square | 90° | Friction, pressure or a need for action. |
| Trine | 120° | Flow, ease or natural compatibility. |
| Opposition | 180° | Polarity, balance or tension across two ends of an axis. |
What an orb means
An aspect does not have to be mathematically exact to be used in astrology. The allowed difference is called the orb. For example, planets 88° apart may still be treated as forming a square if the chosen method allows a 2° difference.
Why orb rules vary
Different astrologers and software use different orb limits, and some allow wider orbs for the Sun and Moon. When comparing charts, check the orb settings before assuming one program has made a mistake.
Applying and separating
Some traditions distinguish an aspect that is moving toward exactness from one moving away from exactness. That distinction requires planetary motion and is a more advanced layer than simply recognizing the aspect angle.
Aspects are different from signs and houses
A sign describes where a planet sits within the zodiac. A house places it within an area of the chart. An aspect describes its angular relationship to another planet or point. You normally need all three layers to understand why two charts with the same Sun sign can look very different.
A simple example
Suppose the Moon and Saturn are close to 90° apart. Astrology would call this a Moon–Saturn square. The interpretation would consider the square's traditional tension, but also the signs, houses and other aspects involved rather than treating one angle as the whole chart.
Do aspects prove anything scientifically?
The angles themselves are measurable positions. The personality or life meanings assigned to them are astrological interpretations, not established scientific effects.
Continue learning
See how to read a birth chart, the orb definition, and the Birth Chart hub.