What a partile aspect is
An aspect is partile when both bodies occupy the same degree of their signs. Sun at 15° Aries trine Saturn at 15° Leo is exact in degrees, not just in tolerance; the tradition took that to mean the aspect operates at full force.
The alternative is platic: the angle is right only within an orb — Sun at 15° Aries and a planet at 21° Leo still fall inside a common 6° trine allowance, but the degrees do not match, and older authorities treated the contact as diluted.
The test is pure arithmetic because the five Ptolemaic angles are all multiples of 30°: adding or subtracting whole signs never changes a degree. So for any major aspect, the difference between the two degrees-in-sign is exactly the aspect's orb. Same degree means a true partile, and nothing else can be.
How we grade exactness
Positions come from sub-arcsecond astronomy (VSOP87/ELP via astronomy-engine). We compute every Ptolemaic aspect in your chart, keep those with an orb of 2° or less — the near-exact cut — and grade each one on the degrees-in-sign.
Four grades, stated plainly: perfect when the two degrees agree within 15 arcminutes; partile when they agree to the same integer degree inside 1°; exact-platic when the orb is under 1° but the pair straddles a degree boundary; near for everything else inside the 2° cut.
The grading is deterministic and the probe pins every branch: a synthetic 15.2°–15.4° opposition grades perfect, a 15.2–15.9 trine grades partile, and a 15.2–14.9 trine — across the degree line — grades exact-platic. Nothing about a grade is fitted after the fact.
What the report returns
One table, sorted by degree gap, every row verified:
- Every major aspect with orb ≤ 2°, graded perfect / partile / exact-platic / near.
- Both bodies with their exact degrees-in-sign, signs and houses.
- The aspect's orb and the degree gap side by side — the arithmetic of the classical test.
- Whether the aspect is applying or separating, from the bodies' daily motions.
- The grading definitions printed under the table, so the labels are never opaque.
A worked example: a perfect trine, 1 January 2000
Our reference chart — London, 1 January 2000, 17:30 UT — contains exactly three near-exact aspects. The top row is the interesting one: the Sun at 10.60° Capricorn trine Saturn at 10.39° Taurus.
Both bodies stand at 10° of their signs; the degrees differ by only 0.211°, which is at the same time the aspect's orb and its degree gap — the arithmetic identity that makes the classical test work.
Inside 15 arcminutes of agreement, the tool grades it perfect: a true partile trine, the chart's strongest single contact by the old standard.
The other two rows show the weaker grades honestly: the Moon at 16.08° Scorpio squares Uranus at 14.82° Aquarius with a 1.257° gap, and Venus at 1.84° Sagittarius sextiles Neptune at 3.20° Aquarius at 1.361° — both near-exact, neither partile. Our automated probe asserts all three rows.
Why exactness was ever a thing
The degree-level reading predates orbs as we use them. In traditional horary and electional work, a partile aspect acted now and wholly; a platic one acted late or partially, if at all — some authorities refused to judge a matter on a platic aspect alone when a partile one was on offer.
Modern practice is gentler: orbs are taken seriously at full value, and few working astrologers gate-read a chart the old way. But the intuition survives because the tightest aspects are usually the ones you can actually point to in a life — contacts that repeat, that trigger on transits at barely a degree of contact.
Use the grades as an attention order rather than a truth order. A perfect Sun trine Saturn deserves to be read first in the 2000 example — will and structure agreeing without friction, at full voltage. A near row is still a real aspect; it is simply one the tradition would have asked you to confirm from other evidence.
For a predictive eye, applying perfect aspects are the sharpest tool in the table: exact, and still moving tighter. The report marks them.
What this tool does not claim
The 2° near-exact cut is our published threshold, not a natural boundary. Raise it and more ordinary aspects join the table at 'near'; drop it to 1° and only the perfect, partile and exact-platic grades remain. The cut is printed in the report so you always know which rule set your table came from.
The perfect/partile split at 15 arcminutes is our stated refinement of 'same degree'. Classical sources did not hand down a decimal standard — they simply said the degrees must agree. We chose 15′ so that a grade is reproducible, and we say so rather than implying ancient blessing.
Partile does not mean fated, and exactness is not importance: a tight minor contact says less about a life than a wide but central one. This is a measurement layer over the same natal aspects every other tool already shows you. All computation runs locally.
Our method in one line
Positions from sub-arcsecond astronomy (VSOP87/ELP via astronomy-engine), read through Porphyry quadrant houses (whole-sign available on every chart). Aspects come from the verified aspect engine; the degree test and its four grades are asserted branch by branch, and on the canonical chart above, by our automated probe (Batch F). Reviewed by Dr. Amara Osei, Astronomy Reviewer.
Step by step
- 1
Enter your birth data
Date, time and place. Degrees-in-sign drive everything, so a precise birth time mainly matters for the Moon.
- 2
Read down the degree gap
The table is sorted by it: the top row is your chart's most literal aspect.
- 3
Separate grades from orbs
Perfect and partile rows are degree-exact; exact-platic rows are orb-tight but degree-straddling — say which you are quoting.
- 4
Check applying rows first
Tip: an applying perfect aspect is the classical trigger — watch when transits reach the same degrees.
Frequently asked questions
- What does partile mean in astrology?
- An aspect is partile when the two planets occupy the same degree within their signs — both at 15°, say — rather than merely falling inside an allowed orb of the exact angle. The classical tradition read partile aspects as operating at full strength, and platic (orb-only) aspects as diluted.
- What is the difference between perfect and partile?
- In our grading, perfect means the degrees agree within 15 arcminutes — effectively the same degree; partile means the same whole-number degree inside one degree of orb. Both are degree-exact in the classical sense; the finer split is our published convention for reproducibility, stated openly rather than presented as tradition.
- How tight is an exact aspect?
- There is no single rule, so we publish ours: a major aspect enters this table when its orb is 2° or less, and only aspects at orb ≤ 1° that also match in degree can earn the partile or perfect grades. Under a wider cut everything within 8° of a trine is a trine; the point of this tool is the minority that are also exact.
- Does an exact aspect matter more?
- Traditionally, yes — the old authorities treated partile aspects as the ones that actually act, and some refused platic ones as sole evidence in a judgment. Modern practice gives orbs full value; a sensible use of this table is ordering your attention, not overriding the rest of the chart.
- Does this tool store or upload my birth data?
- Calculations run entirely in your browser. Your birth data is never uploaded, never stored on a server, and never shared. Every degree comparison and grade is computed inside your browser, and nothing you enter is sent to or kept on any server.
Written by
Elena Marchetti
Founder & Staff Astrologer
Methodology reviewed by
Dr. Amara Osei
Astronomy Reviewer
Published 2026-10-03 · Updated 2026-10-03 · Calculated with sub-arcsecond astronomy (VSOP87/ELP via astronomy-engine)