What Is a Partile Aspect, and How Close Must Synastry Contact Be?

What does partile measure, and what does an orb measure?

Partile describes how close an aspect is under a named convention. Orb gives the measurement: the angular distance between the contact and the exact angle of the aspect. The inclusion limit answers a separate question: which contacts a particular reading method will count or display. Keep these ideas apart. Readers may agree on placements and measured distance yet use different labels or cutoffs. William Lilly’s An Introduction to Astrology draws this distinction through conjunctions. It calls a conjunction at the same degree and minute, when exact, partile; a conjunction within the planets’ orbs but short of exact, platic. Lilly says the same approach applies to other aspects. His text also describes whether a contact falls within those planetary orbs. That is an inclusion rule, not a new aspect angle. Partile does not name another aspect type. It describes closeness to an aspect already identified, such as a square or trine. Nor does the word alone set a synastry chart’s inclusion limit. AstroLibrary defines partile as zero orb and distinguishes it from an aspect within one degree, while reproducing a same-degree-and-minute definition from Sepharial’s New Dictionary of Astrology. These are documented conventions, not a universal cutoff. Report the measured orb first, then name the partile convention and inclusion policy. Readers can then separate calculation from terminology before interpreting the contact.

Sources: An Introduction to Astrology; Definition of Partile in Astrology

How do you calculate the orb from supplied placements?

To calculate an orb, start with the two placements as sign, degree, and minute. Convert each to a position from 0° Aries, measure their angular separation, then compare that separation with the exact angle of the aspect you are testing. The difference, expressed in degrees and minutes, is the orb. William Lilly’s *An Introduction to Astrology* lays out the major aspect angles and discusses how far an aspect falls from exactness; the *Astrology Basics* manual likewise describes orb as the allowable distance from an exact aspect. The examples below are illustrative, not personal chart data. The zodiac has twelve signs, each spanning 30°. assign Aries 0°, Taurus 30°, Gemini 60°, Cancer 90°, Leo 120°, Virgo 150°, Libra 180°, Scorpio 210°, Sagittarius 240°, Capricorn 270°, Aquarius 300°, and Pisces 330°. Add the placement’s degree within its sign, then add its minutes as a fraction of a degree. Keep the minutes through subtraction. The familiar exact angles are conjunction 0°, sextile 60°, square 90°, trine 120°, and opposition 180°. Subtract one longitude from the other and take the absolute value. Above 180°, subtract the result from 360° for the shorter separation. Then subtract the nearest exact aspect angle and take the absolute value again. That final distance is the orb. A separation near 180° is therefore compared with opposition: for example, 178° from conjunction around the circle is 2° from an exact opposition, not a 178° orb. Consider this illustrative square. One placement is at 10°20′ Aries, or 10°20′ from 0° Aries. The other is at 12°05′ Cancer. Cancer begins 90° from Aries, so this placement is at 102°05′. The separation is 102°05′ minus 10°20′, which equals 91°45′. A square is exact at 90°, so subtract 90°00′. The result is 1°45′ from exact: the square’s orb is 1°45′. In decimal form, 45′ is three quarters of a degree, making the orb 1.75°. If the subtraction crosses 0° Aries, use the same circle-wide method rather than treating the zodiac as a straight line with an edge. For instance, positions near the final degrees of Pisces and first degrees of Aries may be only a few degrees apart. Wraparound captures that closeness. Sign names without degrees and minutes cannot provide these longitudes, so they cannot establish an exact orb. Once you have the measurement, you can compare it with a stated inclusion limit and apply a separately named partile convention. The *Aspect Orbs Explained* guide also separates measured orb from a chart tool’s chosen cutoff, reinforcing why those are distinct steps.

Sources: An Introduction to Astrology; Astrology Basics; Orb in Astrology

Which partile conventions produce different answers?

A partile label can change even when the measured positions do not. The difference lies in the rule being applied: does “partile” mean exact geometry, the same numbered degree in both signs, or a small allowed orb? These are documented conventions, not three ways to calculate a different sky. In *An Introduction to Astrology*, William Lilly’s instructional text describes a conjunction in the same degree and minute as partile when exact, then contrasts it with a platic conjunction that falls within the planets’ orbs. It also says the same approach applies to other aspects. AstroLibrary’s entry defines partile as zero orb, and reproduces a definition requiring the same degree and minute. Read together, these sources support a strict exactness usage. They don’t establish that every astrologer uses it. A contemporary alternative appears on Augurine’s Partile Aspects Calculator page. It describes a modern rule of within one degree of exactness and offers a same-numbered-degree option associated there with Lilly. These rules can divide a boundary case differently. The page is one current example, not a survey of astrologers or a ruling standard. Its labels should be reported as that page presents them. Consider an illustrative conjunction across the Pisces-Aries boundary: one position at 29°30′ Pisces and another at 0°15′ Aries. Their zodiacal longitudes differ by 45 minutes, so the conjunction’s measured orb is 0°45′. A strict exact-angle rule says it is close, but not partile, because the orb is not zero. A within-one-degree rule calls it partile. A same-numbered-degree rule does not: one placement is in degree 29, the other in degree 0. The positions and arithmetic stay fixed; only the label changes. A second illustrative comparison shows why “same degree” and “closer to exact” aren’t interchangeable. For a trine, 9°01′ Aries with 9°59′ Leo has a 58-minute orb; both placements carry degree number 9. Change the Leo position to 10°00′, and the orb becomes 59 minutes, still within one degree, but the numbered degrees no longer match. The second pair is slightly farther from exact geometry, yet it qualifies under the one-degree rule and not the same-degree rule. That contrast makes the convention visible instead of hiding it behind a rounded display. The accessible sources don’t support repeating a three-degree threshold as Lilly’s rule. Augurine’s page mentions a separate three-degree band in its own tool options, but that is a provider’s setting, not grounds for attributing a historical rule. When two synastry reports use different labels, compare their stated conventions and the measured orb first. If the positions match, the disagreement may be terminology rather than calculation. Ask which rule was chosen before calling one result an error.

Sources: An Introduction to Astrology; Definition of Partile in Astrology; Partile Aspects Calculator

Why can two synastry charts include different contacts?

A synastry chart’s inclusion limit answers a practical question: which contacts will this method list or draw? It does not define whether a listed contact is partile. Those are separate decisions. A contact may fall inside a chart’s chosen orb and appear in its aspect list while remaining too wide for a particular partile convention. Another chart can omit it because its display uses a narrower limit. The placements have not changed; the rules have. You can see that distinction in two kinds of guidance. The Astrology Basics manual describes orb as the allowable distance from exactness and notes that astrologers may allow wider orbs for the Sun and Moon than for other planets. Its example is a natal-chart guide, so it establishes a configurable way to think about orb, not a synastry rule. In synastry, a method might instead reduce natal allowances to keep a comparison between two charts selective. That is a policy choice about which contacts to include, not a new definition of partile. The accessible NatalChart.AI guide makes the choice concrete by publishing its own synastry settings: it gives six degrees for conjunctions, squares, trines, and oppositions, and four degrees for sextiles. Under that guide’s settings, a contact five degrees from an exact sextile would be outside the listed limit, while a contact five degrees from an exact square would be inside it. This illustrates why “within six degrees” cannot serve as a universal answer for every aspect, chart, or tool. It describes one provider’s settings. The same distinction has an older form. In An Introduction to Astrology, William Lilly discusses planetary orbs and distinguishes an exact aspect from one still within the planets’ allowed orbs. That approach ties consideration to the bodies involved rather than to one modern fixed cap applied to every contact. The text documents a historical method; it does not dictate how a contemporary synastry service must configure its display. Read beside the modern software guide, it shows why two chart makers can adopt different inclusion policies without disagreeing about the measured positions. When two synastry tools show different contacts, compare their settings before treating the difference as a calculation error. Check the aspect type, the bodies involved, and the stated inclusion limit. Then ask whether both tools use the same sign-degree positions and precision. Only after those checks should you compare their contact lists. A six-degree limit is a useful example when a method explicitly adopts it, but it is not a universal synastry standard, and it is not the threshold for partile. Report the measured orb, the inclusion rule, and the chosen partile convention separately. That keeps a software display choice from being mistaken for a difference in the charts themselves.

Sources: Orb in Astrology; Astrology Basics; An Introduction to Astrology

How does a degree-boundary example change the label?

Consider two illustrative pairs forming a trine. In each, the first placement is 9°01′ Aries. The second falls in Leo, where a trine sits about 120° farther along the zodiac. The positions differ by only one minute, yet they sit on opposite sides of a whole-degree boundary. That small change shows why “partile” needs a stated convention. | Pair | Supplied positions | Exact target | Measured orb | Same numbered degree? | Zero-orb rule | Within 1° rule | | --- | --- | --- | --- | --- | --- | --- | | A | 9°01′ Aries and 9°59′ Leo | 120° | 0°58′ | Yes: both are in degree 9 | No | Yes | | B | 9°01′ Aries and 10°00′ Leo | 120° | 0°59′ | No: degrees 9 and 10 | No | Yes | The arithmetic is direct. Aries begins at 0° zodiacal longitude, so the first position is 9°01′. Leo begins 120° later. Pair A’s second placement is therefore 129°59′ Leo longitude, making the separation 120°58′ and the deviation from an exact trine 0°58′. Pair B’s second position is 130°00′, so the separation is 120°59′ and the orb is 0°59′. In both rows, the contact is less than one degree from exact, but neither has zero orb. The distinction between columns matters. AstroLibrary’s “Definition of Partile” gives a zero-orb definition and reproduces Sepharial’s same-degree-and-minute wording. By that exact-angle standard, neither pair is partile. Augurine’s “Free Partile Aspects Calculator” describes a within-one-degree convention and a same-numbered-degree option. Under the one-degree rule, both qualify. Under the same-degree rule, A qualifies and B does not. These are documented conventions, not a vote on which one every astrologer must use. William Lilly’s “An Introduction to Astrology” provides a useful historical comparison: its aspect discussion distinguishes exactness from a looser contact within planetary orbs. That distinction supports keeping measured distance visible rather than letting a label replace the calculation. It does not make every modern label identical to Lilly’s terminology. A display that omits minutes can hide the reason for the split. Pair A’s 9°59′ Leo may be rounded to 10° in one display, even though its listed degree number is 9; Pair B begins at 10°00′. Rounded values can therefore blur the boundary and conceal a one-minute difference in orb. Keep the source precision, compare the actual positions, and state whether “same degree” means the same numbered degree of each sign. The two readers can agree on both placements and both orbs while applying different partile labels. That is a difference in convention, not in the underlying geometry.

Sources: Definition of Partile in Astrology; Partile Aspects Calculator; An Introduction to Astrology

What can closeness tell you about the meaning of a synastry contact?

A close contact deserves attention in a synastry reading, but closeness answers only one question: how near the measured positions are to an exact aspect angle. It doesn't tell you whether the contact feels easy or difficult in the relationship. For that, read the aspect, the planets involved, and the pattern around them. A partile label adds precision to the measurement; it doesn't supply the interpretation. Think of orb as a way to order the chart, not a verdict. When several contacts compete for attention, begin with those closest to exact, then ask what each planet signifies and what kind of aspect connects them. A square and a trine keep their distinct geometries even when one is tighter. Closeness alone can't turn a square into a trine or make one contact more supportive in every context. Consider an illustrative comparison, not a personal chart: one pair of supplied placements forms a close square, while another forms a wider trine. The close square may come first because its measured orb is smaller. The wider trine still belongs in the reading if it falls within the method's inclusion limit. From those facts, you can describe relative exactness and different aspect forms. You can't conclude that the square will cause conflict, that the trine will resolve it, or that either contact determines whether the people should stay together. The example ranks questions; it doesn't answer them before the chart is read. The transcript “Synastry: The Astrology of Relationships” discusses close and wide interaspects and describes how partners may experience the same contact differently. That offers useful interpretive guidance: a contact joins two charts, yet the people need not experience its symbolism in identical ways. The transcript is an astrologers' discussion, not a rule that every close aspect has one fixed effect. Closeness can guide attention, but it can't replace interpretation of the planets, aspect, and lived relationship. A software guide, “Orb in Astrology” from NatalChart.AI, also separates an aspect's measured orb from the settings that determine whether a chart includes it. A contact might qualify under a chosen display policy and still not meet the selected partile convention. Conversely, a very close contact may be called partile under a stated rule while its meaning still depends on the symbols and chart context. Keep measurement, inclusion, and interpretation visible as separate steps. Use closeness to decide what to inspect first, then interpret the contact on its astrological terms. Ask which planets meet, what aspect joins them, and how other chart factors support or complicate the reading. If the chart shows only signs, stay with sign-level themes rather than claiming an exact orb. A precise partile note helps you compare placements consistently; it doesn't score compatibility, establish another person's intentions, or make a relationship decision for you.

Sources: Synastry: The Astrology of Relationships; Orb in Astrology

What information is enough to compare the contact?

To calculate an aspect's orb, you need the zodiacal position of each planet with enough precision to compare their angular distance. That means the sign, degree, and minute for both placements, plus the exact aspect you want to test. A degree-based label such as partile also requires a stated convention. If either placement is known only by sign, you can compare sign relationships, but you cannot tell how close the planets are to an exact angle. Keep the reading at sign level until the missing positions are available. The Astrology Basics manual shows why chart listings include this detail: it describes planetary positions by sign, degree, and minute, and explains that an aspect's orb is the distance from its exact angle. Its example distinguishes a Sun and Moon 9 degrees 30 minutes apart from a pair 10 degrees 5 minutes apart under a 10-degree allowance. Those figures illustrate the manual's example, not a universal synastry rule. For a synastry comparison, gather the same kind of position data for each person's relevant planets. Then identify the angle under review, such as a conjunction, square, trine, sextile, or opposition. A sign pairing can suggest which major aspect might be possible, but signs alone do not show whether the positions sit close to exact or far apart within those signs. Nor can a sign label establish whether a contact meets a degree-based partile definition. Don't fill in missing minutes by guessing. Use the precision shown by the source that supplied the placements. If it rounds to whole degrees, report that limitation rather than implying finer accuracy. William Lilly's An Introduction to Astrology likewise works with planetary positions and degree-based aspect relations in its discussion of aspects. For a reader comparing known placements, that supports a straightforward order: confirm the two positions, name the aspect angle, and only then calculate and label the orb. It does not mean the reader needs a complete birth chart for this specific comparison. The Synastry Comparison Report works from placements you supply, with optional degrees; it does not calculate natal positions from birth details. A missing birth time or absent house data therefore does not supply the missing planetary degrees, and this report should not be treated as a house calculation. You can still make a useful first comparison with signs alone. Note the two signs and the planets involved, then describe the relationship at that level without calling the contact exact or partile. To compare closeness, obtain each planet's sign, degree, and minute from a placement source and keep those values visible. That gives you enough information to reproduce the angular measurement, while leaving the interpretation open to the chosen partile convention and synastry method.

Sources: Astrology Basics; An Introduction to Astrology

How should you report a partile synastry contact?

A useful synastry report makes four things visible: the two placements, the exact aspect angle being tested, the measured orb, and the rules used to label and include the contact. Keep those details together. “Partile” by itself doesn't tell another reader how close the aspect is, and “within orb” doesn't tell them which partile convention you chose. Use a line another reader can check: “Person A’s [planet] at [sign, degree, minute] and Person B’s [planet] at [sign, degree, minute] form a [aspect], exact at [angle]; measured orb: [distance]; partile convention: [named rule]; synastry inclusion limit: [rule and result].” For instance, the boundary comparison in this guide can be reported by carrying forward its two placements and measured orb, then naming whether the selected rule means exact angle, same numbered degree, or within one degree. The label follows the convention; the orb remains the measurement. Keep the inclusion result separate. NatalChart.AI’s “Aspect Orbs Explained” documents one provider’s synastry settings: it lists conjunctions, squares, trines, and oppositions within six degrees, and sextiles within four. Its guide also says that the orb rule determines whether an aspect is listed, and that different rules can produce different lists for the same positions. These figures describe that tool’s policy. They are not a universal synastry standard, and six degrees is not a partile definition. So a report could say, “inside this method’s synastry limit, but not partile under the stated zero-orb convention.” That sentence preserves both results without making them compete. The source for the label belongs in the wording too. AstroLibrary’s “Definition of Partile in Astrology” gives a zero-orb definition and reproduces a Sepharial entry describing bodies at the same degree and minute as partile. That page documents a convention; it does not establish a rule shared by every astrologer. If you use a one-degree rule or a same-degree convention instead, name it plainly. Two people may agree on the placements and orb while using “partile” differently. A transparent report lets them see that the disagreement concerns terminology, not necessarily the chart data. If an input or setting is missing, leave only that field unresolved. With placements and degrees but no stated partile convention, give the measured orb and say the label depends on the convention being applied. With a convention but no inclusion policy, describe the partile classification and mark whether the tool would list the aspect as unknown. If the placements lack degrees and minutes, don’t claim an exact orb or a degree-based partile result. A sign-level comparison can still describe the signs; it cannot fill in missing precision. Report whether the contact appears in the chosen list, falls outside its limit, or cannot be assessed. That status answers a different question from whether it is partile. Keep the measurement, label, and inclusion result distinct, and readers can reproduce your comparison even when their preferred conventions differ.

Sources: Orb in Astrology; Definition of Partile in Astrology

What should you do next with your placements?

Use the degrees and minutes you have, calculate the orb, choose and name one partile convention, and check the contact against a separately stated inclusion limit. With signs alone, hold the reading at sign level. This keeps three judgments visible: measured distance from an exact aspect, the convention behind partile, and the rule that decides which contacts a synastry method includes. As the NatalChart.AI guide illustrates, a tool’s inclusion settings are its own policy; they don’t make every included contact partile. A close measurement gives you a place to begin, not a relationship verdict.

The Synastry Comparison Report can organize Moon, Venus, Mars, and other known placements you supply, with optional degrees. It doesn’t calculate natal positions from birth details. Bring the placements you know, and include degree data when you want an orb comparison. The report can keep inputs and comparisons together; it can’t supply missing positions or decide what a connection means for you.

Choose Compare our placements to work with known inputs. Keep the reported orb beside the partile convention and inclusion limit. Then you can see what the geometry says, what your chosen language adds, and where the available information stops.

A little more clarity