Quintile and Bi-Quintile: The 72° and 144° Aspects in a Birth Chart

← Back to Aspects

The quintile and the bi-quintile are the two minor aspects that come from dividing the zodiac into fifths. Planets 72° apart, one fifth of the circle, form a quintile; planets 144° apart, two fifths, form a bi-quintile. Unlike the major aspects, neither angle fits the twelve signs, so you can only find them by counting degrees. This page explains the geometry, the 2° band it uses, a hand method you can apply to the printed positions of your own chart, and four worked cases, one of them chosen by a fixed rule rather than picked for effect.

About the calculator. The quintile and bi-quintile are educational minor aspects, not features of the site. The free birth chart computes and draws the five major aspects only, and you will not find a quintile or bi-quintile in its aspect list or on its wheel. What it does give you is each planet's sign, degree and minutes, which is all you need to measure these angles by hand. The Astrologist chat receives no planet degrees from your chart and cannot detect a quintile; it can talk about one you have worked out yourself. The figures on this page come from offline calculations using the same routines as the free chart.

Fifths of the circle

360° divided by five is 72°. Stepping round the circle in fifths gives 72°, 144°, 216° and 288°, but separations are always measured the short way round, so 216° is the same as 144° and 288° the same as 72°. That leaves two distinct angles:

• Quintile: 72°, one fifth of the circle.
• Bi-quintile: 144°, two fifths, twice a quintile. It is also written biquintile.

The five major aspects all come from dividing the circle by one, two, three, four or six, which is why they line up with the twelve signs. Five does not divide twelve, so the quintile family stands apart from the sign system entirely. Some astrologers call it the fifth-harmonic family for that reason.

Why the signs do not help

A quintile is two signs and 12°; a bi-quintile is four signs and 24°. Neither is a whole number of signs, so the sign pair alone never tells you whether one is present:

• 10° Aries and 22° Gemini are exactly 72° apart. Move the second planet to 29° Gemini and the gap becomes 79°, well outside any quintile band, in the same two signs.
• 26° Aries and 7° Cancer are 71° apart, a quintile under this page's band, though the signs are three apart rather than two.
• From 1° Aries, a bi-quintile falls at 25° Leo going forward and at 7° Scorpio going back: four signs away in one direction, five in the other.

For that reason this page has no sign-pair table and no "in-sign" label for these aspects. Count the degrees every time.

The 2° working band

Here, a quintile means a separation from 70° to 74°, and a bi-quintile one from 142° to 146°, both limits included: no more than 2° from exact in zodiac longitude. The band is the same for every pair of planets, with no bonus for the Sun or Moon.

That is the convention of this guide, picked so the examples can be checked by anyone. It is not a calculator rule and it leaves the site's major-aspect orbs (see aspect orbs) untouched. Other sources draw the line elsewhere:

• TimePassages' desktop program lists 2° as its default natal orb for both the quintile and the bi-quintile. Its mobile and web apps use a tighter 1° for the bi-quintile, and the software adds half again when the Sun or Moon is involved.
• Astrodienst's Astrowiki article on the quintile gives an orb of 2 to 3 degrees.
• Astrotheme uses 0.8° for both in natal charts.

Two astrologers using different bands can disagree about the same chart without either being wrong. The 2° figure here is one reproducible choice inside that range.

Measuring a quintile from your chart

Take the two planets' positions from the planet table under the free chart and work in zodiac longitude, counting from 0° Aries.

1. Longitude. Sign start plus degrees plus minutes: Aries 0, Taurus 30, Gemini 60, Cancer 90, Leo 120, Virgo 150, Libra 180, Scorpio 210, Sagittarius 240, Capricorn 270, Aquarius 300, Pisces 330. So 9°59′ Libra is 189°59′.
2. Gap. Subtract the smaller longitude from the larger. If that leaves more than 180°, subtract it from 360° to get the short-way separation.
3. Test. Is the separation between 70° and 74°? Then it is a quintile under this band. Between 142° and 146°? A bi-quintile.

The test uses longitude alone. Declination, celestial latitude, mundane positions and applying or separating motion play no part in it.

Printed minutes and the edge. The free chart shows whole minutes with the seconds cut off, so any hand result carries an uncertainty of a minute or two. A result within about 2′ of the 2° line (1°58′ to 2°02′ from exact, for instance) is boundary-sensitive: report it as too close to call from the printed figures rather than as a yes or a no.

Bodies covered. The Sun through Pluto only. The lunar Nodes, Chiron, Lilith and the chart angles are not part of this method. A quintile between two outer planets lasts a long time and is shared by a whole generation, so it is not read here as a personal trait.

Sun, Mercury and Venus

Mercury and Venus stay close to the Sun, so some quintile contacts between the three are impossible. Rechecking the site's own measured maxima over daily noon charts from 1900 to 2099 (the method is on which Sun, Mercury and Venus aspects are possible):

Under this band, then, only Mercury and Venus can form a quintile, and only when they sit on opposite sides of the Sun near their widest spread; none of the three pairs can form a bi-quintile. This is the site's measured reference geometry from daily samples rather than a formal proof, but none of the impossible cases comes close to the line.

Worked examples

Positions come from the production chart routines, recalculated for this page. The hand arithmetic uses the printed, truncated minutes.

Noor: a clean quintile

Noor, Amsterdam, 2 December 1992, 21:30. Mars is at 27°31′ Cancer (retrograde) and Jupiter at 9°59′ Libra.

• Longitudes: 117°31′ and 189°59′.
• Gap: 72°28′.
• From exact 72°: 0°28′, a quintile under this band, far from the edge.

Checked minute by minute across her birth date, the pair stays between about 72.3° and 72.5°, so the quintile holds whatever her exact time.

A bi-quintile chosen by rule

None of the three recurring example charts has a bi-quintile within 2°. Rather than hunt for a flattering case, this page fixed a rule in advance: take the first noon in London, counting forward from 1 January 2000, at which any pair of planets other than the Moon is within 0.25° of 144°, breaking any tie on the same date by the usual planet order (Sun, Mercury, Venus, Mars and so on). The date and place teach the arithmetic only; nobody's biography is attached.

The rule lands on 13 January 2000, 12:00 GMT, London, with a single qualifying pair: Venus at 16°08′ Sagittarius and Saturn at 10°17′ Taurus.

• Longitudes: 256°08′ and 40°17′.
• Gap: 215°51′, more than 180°, so the separation is 360° − 215°51′ = 144°09′.
• From exact 144°: 0°09′, a bi-quintile under this band.

Run across every minute of that London date, the separation stays between about 143.5° and 144.8°, inside the band all day.

Lotte: a slow-planet quintile

Lotte, Utrecht, 27 August 1991, 06:55. Saturn is at 1°22′ Aquarius (retrograde) and Pluto at 17°48′ Scorpio: 301°22′ and 227°48′, a gap of 73°34′, 1°34′ from exact, inside the band. The pair barely moves through the day (about 73.51° to 73.59°). Saturn and Pluto are both slow, so a contact like this one is shared by many people born in the same months; on this page it illustrates the arithmetic rather than a personal reading.

Lotte: a Moon quintile that needs the time

Lotte's Moon at 24°36′ Pisces (354°36′) and Neptune at 14°13′ Capricorn, retrograde (284°13′) are 70°23′ apart at her stated time, 1°37′ from exact and inside the band. Across the date the separation runs from about 66.7° at midnight to about 79.5° at 23:59, and it is inside the band only from about 06:12 to 13:43. With her recorded time the quintile stands; without it, it could not be claimed.

No contact above shows on the free chart, because none falls inside a major-aspect orb.

When the birth time is unknown

A Moon quintile or bi-quintile needs a reliable birth time, or a check at every minute of the full possible birth window that comes out the same throughout. Lotte's Moon-Neptune pair shows how quickly the answer can change. Slower pairs are not stable by default either: they need the same whole-date check before you can say the time does not matter, as was done for Noor's Mars-Jupiter pair above. The noon placeholder that charts use for an unknown time is a reference, never your birth moment. See your birth chart without a birth time for the wider picture.

How astrologers tend to describe the quintile family

Readings of the quintile and bi-quintile vary more than those of the major aspects, and many astrologers leave them out. Where they are used, some astrologers associate this family with craft, style, pattern-making, or a distinctive way of shaping and organising something, often with the two planets suggesting what is being shaped. Popular writing sometimes makes far larger claims for the quintile. This page does not: a 72° angle between two planets says nothing measurable about what anyone can do or will achieve, and the vocabulary above is offered as other astrologers' language for discussion, not as a description of you.

Planet meanings still set the subject; planet meanings covers them. Like other minor aspects, the quintile family is usually read as a detail beside the five major aspects, not as the main structure of a chart.

History in brief

Johannes Kepler proposed three new aspects in the early seventeenth century: the quintile (72°), the bi-quintile (144°) and the sesquiquadrate (135°, covered on semi-square and sesquiquadrate). He related them to musical ratios and the geometry of regular figures, setting the idea out most fully in Harmonices Mundi, and said he had checked their effects against years of weather observations. Within a few decades William Lilly's Christian Astrology (1647) was giving instructions for finding them. Much later, the twentieth-century astrologer John Addey developed harmonic astrology, an approach that studies divisions of the circle such as fifths. These points follow the Skyscript article "Johannes Kepler: Music of the Spheres".

Where this page fits

The minor aspects overview introduces the smaller angles in general, and the quincunx page covers the 150° contact. For the square-based minor pair, including Kepler's third new aspect, see the semi-square and sesquiquadrate. Quintiles do not enter the site's aspect count (how many aspects a birth chart has counts the five majors), and a planet with only quintile contacts is still unaspected under the five-aspect test; unaspected or not: borderline cases discusses that choice. The methodology page sets out what the calculator computes, and the Aspects library lists every guide.

Related articles

• Semi-Square and Sesquiquadrate: The 45° and 135° Aspects
• Quincunx (Inconjunct) Aspect
• Minor Aspects in Astrology
• Aspect Orbs in Astrology
• Major Aspects in Astrology
• Sun, Mercury and Venus: Which Aspects Are Possible?
• How Many Aspects Does a Birth Chart Have?

Ask about a quintile you have measured →