Geometry first
What does an exact aspect mean in astrology?
An exact aspect occurs when the smallest angular separation between two relevant chart positions matches the aspect's exact target angle: 0° for a conjunction, 60° for a sextile, 90° for a square, 120° for a trine, or 180° for an opposition.
Exactness is different from being within orb. A separation that does not match the target exactly may still be recognized as an aspect when its difference from the target falls within the applicable orb policy. AstroMethod uses context-specific orb policies rather than one universal allowance.
What an aspect is not
A relationship, not an actor or location
Planets describe the functions being related. Zodiac signs describe styles of expression. Houses describe life areas or chart contexts.
An aspect describes how two functions connect. It does not replace the planets, signs, houses, or the wider pattern of the chart.
Explore all five major aspects
Astrology aspect symbols and angles
Each major aspect has a canonical symbol and exact target angle. Select an entry for its full geometry, meaning, natal interpretation, Synastry context, and applicable orb policies.
Conjunction
Symbol ☌. Exact 0°
A conjunction occurs when two chart points occupy the same part of the zodiac, with an exact angular separation of 0°.
Read the full reference →Sextile
Symbol ⚹. Exact 60°
A sextile is a 60° angular relationship between two chart points and is represented by the calculation symbol ⚹.
Read the full reference →Square
Symbol □. Exact 90°
A square is a 90° angular relationship between two chart points, represented by the symbol □.
Read the full reference →Trine
Symbol △. Exact 120°
A trine is a 120° angular relationship between two chart points, represented by the symbol △.
Read the full reference →Opposition
Symbol ☍. Exact 180°
An opposition is a 180° angular relationship between two chart points, represented by the symbol ☍.
Read the full reference →Deterministic geometry
How are aspects calculated in astrology?
AstroMethod calculates aspects from chart positions through a fixed geometric process:
- 1Determine the tropical zodiac longitude of each planet or supported chart point.
- 2Calculate the smallest angular separation between the two positions, including pairs that cross the 0° and 360° zodiac boundary.
- 3Compare that separation with the supported exact aspect angles: 0°, 60°, 90°, 120°, and 180°.
- 4Calculate the orb difference: the absolute difference between the observed separation and the exact target angle.
- 5Check whether that difference falls within the orb policy for the relevant calculation context.
For example, positions at 10° and 100° have a smallest separation of 90°, making their square exact. If the separation were 92°, the square would have a 2° orb difference and would be recognized only if the applicable square policy allows that difference.
How aspects appear
Lines connect the represented chart points
In a chart wheel, aspect lines connect the two supplied endpoints and may use different colours, line treatments, or midpoint glyphs to keep the five relationships distinguishable. Those visual choices present calculated facts; they do not alter the planets' true longitudes, the aspect type, or the orb.
The reference symbol for Sextile is ⚹. The shared interactive chart intentionally uses ✶ as a visual presentation variant. The calculation identity and exact 60° geometry remain unchanged.
Context-specific thresholds
There is no single universal orb here
Different calculations answer different questions, so this repository intentionally uses separate default policies. The exact angle never changes. The maximum accepted difference from that angle depends on whether the calculation concerns planet-to-planet sky or natal geometry, personal transits to a natal chart, or chart-to-chart Synastry.
Current-sky and natal planet aspects
Used by the repository's default planet-to-planet major-aspect calculation, including the natal chart's planetary aspects.
- Conjunction
- ±8°
- Sextile
- ±4°
- Square
- ±6°
- Trine
- ±6°
- Opposition
- ±8°
Personal transit-to-natal aspects
Used when a current transiting planet is compared with a natal planet in the personal transit system.
- Conjunction
- ±3°
- Sextile
- ±2°
- Square
- ±3°
- Trine
- ±3°
- Opposition
- ±3°
Compatibility and Synastry aspects
Used when a supported point in Person A's chart is compared with a supported point in Person B's chart.
- Conjunction
- ±6°
- Sextile
- ±4°
- Square
- ±5°
- Trine
- ±5°
- Opposition
- ±6°
Aspect contexts
Birth Chart
Natal relationships
Natal aspects connect planetary functions at the birth instant. Their meaning belongs within the complete pattern of planets, signs, Placidus houses, and other aspects.
Current sky
Transit geometry
Current-sky aspects describe calculated angular relationships among moving planets. Exact aspect events can also provide timing evidence without making deterministic predictions.
Compatibility
Cross-chart Synastry
Synastry compares supported points across two complete charts. An aspect describes symbolic interaction, not relationship history, quality, destiny, or guaranteed outcomes.