Aspect Orbs

Orbs determine the range within which two celestial bodies are considered to form an aspect. AstroAPI uses carefully tuned default orbs for each chart type, but you can override them when needed.

What Are Orbs?

An orb is the allowable deviation from the exact aspect angle. For example, a conjunction occurs when two planets are at 0° apart. With an orb of 8°, planets anywhere from 0° to 8° apart would be considered in conjunction.

Default Orbs by Chart Type

AstroAPI uses different default orbs for different chart types, reflecting astrological best practices:

Natal Charts

Aspect	Angle	Default Orb
Conjunction	0°	8°
Opposition	180°	8°
Trine	120°	8°
Square	90°	8°
Sextile	60°	6°
Quincunx	150°	4°
Semisextile	30°	3°
Quintile	72°	2°
Biquintile	144°	2°
Octile	45°	2°
Trioctile	135°	2°

Transit Charts

Transit aspects use tighter orbs because they indicate timing:

Aspect	Angle	Default Orb
Conjunction	0°	2.6°
Opposition	180°	2.5°
Trine	120°	2.3°
Square	90°	2.3°
Sextile	60°	2.3°
Quincunx	150°	2°

Synastry Charts

Synastry uses variable orbs based on the planets involved:

• Sun/Moon conjunctions and oppositions: Max 5°
• Other Sun/Moon aspects (trine, square, sextile): Max 3°
• All other planet combinations: Max 3°

Composite Charts

Composite charts use a consistent 2.5° orb for all major aspects.

Solar Return & Lunar Return Charts

Return charts use a 6° orb for all major aspects.

Secondary Progressions

Progressions use very tight orbs of 1° for all aspects due to the slow movement of progressed planets.

Custom Orbs

You can override the default orbs by including an orbs object in your request. Only specify the aspects you want to customize - unspecified aspects will use their defaults.

Example: Custom Orbs for Natal Chart

{
  "dateTime": "1990-06-15T14:30",
  "location": {
    "latitude": 51.5074,
    "longitude": -0.1278,
    "timezone": "Europe/London"
  },
  "orbs": {
    "conjunction": 10,
    "opposition": 10,
    "trine": 6,
    "square": 6
  }
}

Example: Tight Orbs for Precision

{
  "dateTime": "1990-06-15T14:30",
  "location": {
    "latitude": 51.5074,
    "longitude": -0.1278,
    "timezone": "Europe/London"
  },
  "orbs": {
    "conjunction": 3,
    "opposition": 3,
    "trine": 2,
    "square": 2,
    "sextile": 2
  }
}

Available Aspect Types

Aspect ID	Name	Angle
conjunction	Conjunction	0°
opposition	Opposition	180°
trine	Trine	120°
square	Square	90°
sextile	Sextile	60°
quincunx	Quincunx/Inconjunct	150°
semisextile	Semisextile	30°
quintile	Quintile	72°
biquintile	Biquintile	144°
octile	Octile/Semisquare	45°
trioctile	Trioctile/Sesquiquadrate	135°
decile	Decile	36°
tridecile	Tridecile	108°

Best Practices

1. Use defaults for most cases - The default orbs are carefully chosen based on astrological tradition and work well for most applications.

2. Tighter orbs for prediction - When looking for precise timing (transits, progressions), use tighter orbs.

3. Wider orbs for relationship analysis - Synastry and natal charts can benefit from slightly wider orbs to catch all significant connections.

4. Luminaries deserve wider orbs - The Sun and Moon traditionally receive wider orbs than other planets due to their astrological importance.

5. Minor aspects need tight orbs - Aspects like quintile, semisextile, and octile should use orbs of 2° or less to ensure significance.

Supported Endpoints

Custom orbs are supported on the following endpoints:

• /calc/natal - Natal chart calculation
• /calc/synastry - Synastry chart calculation
• /calc/composite - Composite chart calculation
• /calc/solar-return - Solar return calculation
• /calc/lunar-return - Lunar return calculation