Free Minor Aspects Calculator

A minor aspect is any planetary angle drawn from dividing the 360° circle by 5, 7, 9, 10, 11, or 20. The six covered here are septile (51°25'), novile (40°), decile (36°), undecile (32°44'), vigintile (18°), and biquintile (144°).

The scanner reads your full chart and flags every instance plus any pattern those instances form: Septile Triangle, Novile Triangle, Bi-Novile Chain, and the very rare Grand Decile.

That is the conventional answer. Here is the position this tool actually takes: minor aspects are not weak major aspects. They are a different signal. A septile asks what the planet is for, not how it gets along with the other planet. A novile points at completion. A decile points at craft. The interpretations work because the geometry of 7, 9, and 10 carries those meanings everywhere else in the universe too. Music does this. Crystallography does this. Astrology is using the same arithmetic.

Minor aspects need tighter orbs than major aspects. Not because they are weaker. Because they are more frequency-specific. A septile six degrees off the exact angle is not a wide septile, it is noise. The defaults this tool uses:

• 1.5° for septile and novile families
• 1° for decile family
• 2° for biquintile
• 1° for undecile, 0.75° for vigintile, our tightest defaults because those two families have the lowest interpretive reliability

Tighten further if you want only the unambiguous hits. Widen if you are chasing a theory. We don't recommend going past loose, the highest harmonics get drowned out by overlapping major-aspect noise once the orb opens up. If your default chart software runs 8° orbs on everything, your septiles are already buried.

The other reading principle: not every minor aspect deserves a story. A single 1°45' decile between Mercury and Mars is real. One 1° vigintile between your Part of Fortune and Chiron is probably geometry doing its job and nothing more. Look for repetition. Three septiles in a chart is a thread. One septile is a thread end.

Patterns matter more than single aspects in this family. A scattered chart with one of each minor aspect does not read as anything in particular. A chart with three septiles in a tight cluster reads as a septile-dominant person, and a chart with a Grand Septile Triangle reads as someone whose entire vocational arc is keyed to 7.

• Septile Triangle. Three planets connected by septile-family aspects. Three full septiles cannot form an equilateral triangle on a 360° circle (51.43° × 3 = 154.29°, not 360°), so the triangle is always a mix of septile, bi-septile, and tri-septile contacts. Rare enough that finding one is the kind of thing astrologers email each other about.
• Novile Triangle. Three planets connected by novile-family aspects. Less rare than a Septile Triangle but still meaningful when present. Often correlates with one specific area of life that finishes itself.
• Bi-Novile Chain. Three or more planets each 80° apart in a chain. Common in charts with strong dharmic themes.
• Grand Decile. Five planets connected by decile and quintile family aspects, forming a fivefold pentagon. Astronomically rare. If you have one, the fivefold harmonic dominates the chart and applied creative skill becomes the organizing principle.

Patterns appear at the top of the result block above the aspect list. Patterns are the headline; individual aspects are the supporting cast.

Every minor aspect on this page becomes a conjunction in its corresponding harmonic chart. A septile in the natal chart becomes a 7th-harmonic conjunction. A novile becomes a 9th-harmonic conjunction. The math is identical: dividing the circle by N collapses every aspect-of-N back to 0°.

What that means in practice: if this scanner finds three septiles in your chart, your 7th harmonic chart is going to show three conjunctions, and those conjunctions tell you which planets are actually doing the 7th-harmonic work. The harmonic chart is the magnifying glass; this scanner tells you whether you need it.

Follow the thread with our Harmonic Chart Calculator (set H=7 for septile-heavy charts, H=9 for novile-heavy, H=5 for quintile-family) or read the harmonic charts learn guide for the longer theoretical case.

Four concrete differences.

1. Pattern detection in-line. Astro-Seek detects patterns but buries them in a separate Shape tab. AstrologyM does not detect harmonic patterns at all. This scanner surfaces Septile Triangles, Novile Triangles, and Bi-Novile Chains at the top of the result.
2. Harmonic family labels on every aspect. Each hit comes tagged with its harmonic (5, 7, 9, 10, 11, 20). That is the connection most calculators omit, and it is the connection that makes the reading land.
3. Honest aspect ranking. Septile, novile, decile, and biquintile carry real interpretive weight. We flag undecile and vigintile contacts as speculative so you know not to over- read them. Most calculators present all minor aspects as equally weighted, which they are not.
4. ANISE / JPL ephemeris under the hood. The same engine NASA uses for spacecraft trajectory, not the Swiss Ephemeris most legacy astrology tools default to. The arithmetic comes out within a fraction of an arc-second of the same answer, but the data lineage is cleaner and the calculator stays accurate at extreme latitudes and historical dates where Swiss-based tools start to drift.

For adjacent aspects: the Quintile Calculator covers the 72° quintile (and overlaps on biquintile). The Quindecile Calculator covers the 165° obsession aspect (24th harmonic). The Semi-Sextile Calculator covers the 30° contact. Each lives at its own URL by design so we can give each family the depth it needs.