Libra and Sagittarius compatibility gets a lot of searches in the US. Most answers list traits and hand out a score. This page does something else. I counted real US births to see how many times chance puts a Libra with a Sagittarius. I measured the true angle between their Suns. And I read the old books to check a claim you see everywhere: that this is the one pair ruled by the two lucky planets. The short version: about 1 US couple in 74 is a Libra and a Sagittarius. Only one pair in three has a true sextile. And the lucky planet claim is half right.
Start with what no one can promise
Astrology is not a science. No study has shown that a Sun sign predicts whether a couple will last. The largest test I know of was run by David Voas, a researcher at the University of Manchester, in 2007. He took the 2001 census of England and Wales. He looked at the birth dates of 10.3 million married couples. He found no sign pair that married more than chance would allow. His corrected table shows that the small excess of couples who share a sign came from errors on the forms. The Skeptical Inquirer reported his result in March 2008.
So this page does not rate the match. It treats the pair as a way of reading two people, a lens and not a forecast. The lens can still help. It gives two partners words for how each one works. It shows where they can talk past each other. But the stars do not decide the outcome. The two people do.
Voas’s result has one more use. If signs do not steer who marries whom, a Libra meets a Sagittarius at the rate set by birth counts alone. That rate can be measured, so I measured it.
The odds that a Libra and a Sagittarius meet in the US
A sign is not one twelfth of the year. The Sun moves faster in our winter, when Earth is closest to it. Over the years 1600 to 2400, it spends 30.4 days in Libra on average. It spends 29.6 days in Sagittarius, the second shortest stay of the twelve, as our Sagittarius sign page shows. US births are not flat through the year either. They peak in late summer and early fall. They dip in late fall and winter.
I took two public files of daily US births. The first holds Social Security counts for 2000 to 2014, about 62.2 million births. The second holds counts from the National Center for Health Statistics for 1994 to 2003, about 39.7 million births. For each day, I found the exact moment the Sun changed sign. When the change fell inside a day, I split that day’s births by the hours on each side.
| Question | Social Security file, 2000 to 2014 | Health Statistics file, 1994 to 2003 |
|---|---|---|
| Share of US births with the Sun in Libra. | 8.52 percent. | 8.51 percent. |
| Share of US births with the Sun in Sagittarius. | 7.95 percent. | 7.90 percent. |
| Rank of Libra among the twelve signs. | Fifth of twelve. | Fifth of twelve. |
| Rank of Sagittarius among the twelve signs. | Tenth of twelve. | Eleventh of twelve. |
| Chance that two people drawn at random are one Libra and one Sagittarius. | 1.35 percent, or 1 pair in 74. | 1.34 percent, or 1 pair in 74. |
If all signs were equal, the pair would turn up once in 72 draws. This one turns up once in 74. So it sits very close to plain chance. The two signs pull in opposite ways, and they nearly cancel out.
Libra rides the end of the fall peak in births. Its share of births is about 2 percent above its share of the calendar. Sagittarius falls in the late fall dip, and the Sun moves fast there. Its share of births is about 2 percent below its share of the calendar. In both files, it is one of the three rarest Sun signs.
What does 1 in 74 mean in real life? Put 74 random couples in a room. About one of them will be a Libra with a Sagittarius, in one order or the other. That is not rare. It is what chance gives the average pair of signs, give or take a little.
Two signs apart: the sextile, and the share of pairs that truly have it
Count along the zodiac from Libra. Scorpio is one step on, then Sagittarius. Two signs apart means 60 degrees on the circle. Astrologers call that angle a sextile. They read it as a friendly link, an open door that still needs someone to walk through it. Libra is an air sign and Sagittarius is a fire sign. Air feeds fire, so the pair is read as lively.
Scorpio, the sign in between, forms its own pair with the Archer, covered in our guide to Scorpio and Sagittarius compatibility.
Here is the catch. A sign is a slice 30 degrees wide. A Libra born on the first day of Libra and a Sagittarius born on the last day of Sagittarius have Suns about 90 degrees apart. A late Libra and an early Sagittarius can be only about 30 degrees apart. The label says 60, but the real gap runs anywhere from 30 to 90 degrees.
Most astrologers only count an aspect when the angle is close to exact. An aspect is a set angle between two points in the sky. The leeway around the exact angle is called the orb. For a sextile, a common modern orb is 4 to 6 degrees. So I asked a plain question. For a Libra and a Sagittarius picked at random from US births, what share of pairs have Suns within a given orb of 60 degrees?
| Orb allowed around 60 degrees | Share of Libra and Sagittarius pairs with a true sextile |
|---|---|
| Within 3 degrees. | 19 percent of pairs. |
| Within 6 degrees. | 36 percent of pairs. |
| Within 8 degrees. | 46 percent of pairs. |
| Within 10 degrees. | 56 percent of pairs. |
With a 6 degree orb, about one pair in three has a real Sun sextile. Even with 8 degrees, fewer than half do. The other pairs share the label, not the angle. About one pair in nine has Suns closer than 45 degrees. About one pair in seven has them wider than 75 degrees.
These shares are the same for any two signs a few steps apart. The width of a sign alone sets them. Our page on Libra and Capricorn compatibility found the same one in three for its square.
A true sextile needs birthdays about 60 days apart
For the angle to be exact, both Suns must sit at the same degree of their signs. From one degree of Libra to the same degree of Sagittarius, the Sun takes between 59.5 and 60.3 days. The gap shrinks a little toward the end of the signs, as the Sun speeds up on its way to early January.
So take a Libra born about October 8. The Sun then sits near 15 degrees of Libra. A Sagittarius born about December 6 or 7 has the Sun near 15 degrees of Sagittarius. That pair has the exact sextile the books describe. Now take a Libra born on September 23 and a Sagittarius born on December 21. Their Suns sit close to 90 degrees apart. That is a square in size, not a sextile. If you want to use the angle, look up both birth dates and find the real degrees.
The two lucky planets: checking the claim
Each sign has a ruling planet, the planet in charge of it. Libra belongs to Venus. Sagittarius belongs to Jupiter. The old books call these two the good planets, or benefics. In Book 1, chapter 5 of the Tetrabiblos, Ptolemy names Jupiter and Venus, with the Moon, as the planets that do good. He wrote around 150 AD in Alexandria. I read him in the Robbins English version of 1940. In 1647, William Lilly calls Jupiter the greater fortune and Venus the lesser fortune.
You will read that Libra and Sagittarius are the only pair of signs ruled by the two benefics and linked by a sextile. I checked it, and it is not quite true. Venus rules two signs, Taurus and Libra. Jupiter rules two signs, Sagittarius and Pisces. That gives four pairs with one sign from each planet.
| Pair ruled by Venus and Jupiter | Distance between the signs | How Ptolemy reads it |
|---|---|---|
| Libra and Sagittarius. | Two signs, a sextile. | A link in harmony. |
| Taurus and Pisces. | Two signs, a sextile. | A link in harmony. |
| Taurus and Sagittarius. | Five signs apart. | No link, the signs are strangers. |
| Libra and Pisces. | Five signs apart. | No link, the signs are strangers. |
So there are two benefic sextiles, not one. Taurus and Pisces is the other. The two differ in a clear way. Taurus and Pisces are both feminine signs, in Ptolemy’s terms. Libra and Sagittarius are both masculine. So this is the only benefic sextile between masculine signs, the signs of air and fire.
Of the two pairs of strangers in the table, our page on Taurus and Sagittarius compatibility finds one that came last in a census of married couples.
A friendship with no debts
The two sextiles differ in one more way. Venus is exalted in Pisces. Exaltation is a second place of honor, where a planet is a guest of high rank. So Taurus and Pisces are tied twice: Venus rules one sign and is honored in the other.
Libra and Sagittarius have no such tie. I checked Ptolemy’s lists of homes, elements and exaltations in Book 1, chapters 17 to 19. Venus holds no major rank in Sagittarius, only a few degrees called its terms. Its element rulers are the Sun by day and Jupiter by night. Jupiter holds no major rank in Libra either. The air signs go to Saturn by day and Mercury by night. And neither planet is weak in the other’s sign. Venus is in exile in Aries and Scorpio, and in fall in Virgo. Jupiter is in exile in Gemini and Virgo, and in fall in Capricorn.
So each ruler is a stranger in the other’s house, but a kind one. Neither owes the other, and neither harms the other. The old picture is two hosts who both like guests. In the tradition, that fits a pair built on ease and good company more than on need.
Both look toward the Sun’s own sign
Ptolemy gives one more detail in chapter 17. He sets the homes of the planets around Leo, the home of the Sun. Venus gets Libra, which sits a sextile from Leo. Jupiter gets Sagittarius, which sits a trine from Leo, 120 degrees away. He calls both angles harmonious. So both signs of this pair face the Sun’s home on good terms.
What else the oldest book says
Ptolemy sorts the signs in several more ways. Here is what each one says about Libra and Sagittarius.
Same kind, so a harmonious angle
Ptolemy splits the signs into masculine and feminine, one after the other around the circle. Libra and Sagittarius are both masculine. In chapter 13, he says the sextile and the trine are in harmony because they join signs of the same kind. The square and the opposition clash because they join signs of opposite kinds. So the easy reading of this pair is old. It rests on a rule about kinds of signs, not on a study of couples.
No other tie in his list
Ptolemy names three more ties between signs. Some signs command and others obey. They sit at the same distance from the equinox. Some signs behold each other, since the Sun gives them days of the same length. Some signs are strangers, with no tie at all. Those sit one or five signs apart.
I checked each list, by whole signs and by exact degrees. Neither reading ties Libra to Sagittarius. So the sextile is the only tie between this pair. They are not strangers, since the sextile is a true aspect.
An equinox sign and a solstice sign
The Sun enters Libra at the September equinox, when day and night are equal. Our Libra sign page explains why the two moments are the same. Sagittarius ends at the December solstice, the shortest day of the year. Ptolemy notes in chapter 18 that Sagittarius lies toward the winter turn of the year. Libra starts things, and modern books call it a cardinal sign. Sagittarius closes a season, and modern books call it a mutable sign, one that adapts. So one partner opens and the other one moves on.
Where each partner’s Venus and Jupiter can sit
Venus orbits closer to the Sun than Earth does. From here, it never strays more than about 47 degrees from the Sun. That limit boxes in the Venus sign of each partner. I measured the split over the years 1600 to 2400.
| Venus sign | Share of people with the Sun in Libra | Share of people with the Sun in Sagittarius |
|---|---|---|
| Leo. | 8.90 percent. | Never, 0 percent. |
| Virgo. | 29.24 percent. | Never, 0 percent. |
| Libra. | 23.52 percent. | 9.30 percent. |
| Scorpio. | 28.97 percent. | 28.45 percent. |
| Sagittarius. | 9.37 percent. | 23.89 percent. |
| Capricorn. | Never, 0 percent. | 28.62 percent. |
| Aquarius. | Never, 0 percent. | 9.74 percent. |
Look at the crossing. About one Libra in eleven has Venus in Sagittarius. About one Sagittarius in eleven has Venus in Libra, where Venus is at home. So some pairs mirror each other: each one carries the Sun sign of the other in the planet of love. The Libra and Capricorn pair can never do that.
The two partners can share a Venus sign in three cases: Libra, Scorpio or Sagittarius. If birth dates are not linked, about one Libra and Sagittarius pair in eight has the same Venus sign. Scorpio gives most of those.
The rulers are rarely at home. Venus rules Libra, yet a Libra has Venus in Libra in only 23.52 percent of cases. Jupiter rules Sagittarius, yet a Sagittarius has Jupiter there in only 10.22 percent of cases. Both at once, in one couple, comes to about 1 pair in 42. So most of these couples carry their rulers somewhere else, and that place shapes how each one loves.
How the pair can play out day to day
Here the language turns from counts to tradition. What follows is how astrologers read the two signs. It is a set of images to test against your own life, not a set of facts.
What each partner brings
Libra is a cardinal air sign. Air means ideas, talk and links between people. A Libra partner shows care through fairness and grace. They weigh both sides. They notice when a room feels off, and they want to set it right.
Sagittarius is a mutable fire sign. Fire means drive, warmth and faith in what comes next. A Sagittarius partner shows care through honesty and shared adventure. They want to learn, to travel and to laugh. They say what they think.
Where they meet
Both signs like people, talk and new ideas. Both are more at ease in the world than at home alone. Libra brings tact to the Archer’s bold plans. Sagittarius brings a wider view to Libra’s search for balance. In the old picture, Venus adds beauty and Jupiter adds room to grow.
Where they rub
The friction is soft, but it is real. Libra wants peace in the room. Sagittarius wants the truth said out loud. When Sagittarius speaks bluntly, Libra can hear a lack of care. When Libra smooths things over, Sagittarius can hear a lack of spine.
Plans are the other sore spot. Libra likes a clear shared frame. Sagittarius likes to keep doors open. Libra can read that as a lack of commitment. Sagittarius can read a fixed plan as a cage.
What helps, in the words of the tradition
The sextile is read as a chance, not a gift. It opens a door, but someone has to use it. In plain terms, that means a few simple habits:
- Say the hard thing kindly, and say it soon.
- Name what you need out loud, rather than hint at it.
- Keep one fixed ritual each week, and leave the rest of the week open.
- Plan trips together, with free days built in.
- Take turns choosing how you spend a night out.
These habits are not astrology. They help most couples. The signs only give a name to the pattern.
Look past the Sun
A Sun sign is one point in a chart with ten planets and twelve houses. To read two people well, astrologers compare whole charts. That method is called synastry. It looks at how each planet in one chart meets each planet in the other.
Three placements matter most for love in the traditional view. The Moon shows needs and moods. Venus shows what someone finds lovely and how they give affection. Mars shows desire and how someone pushes for what they want.
The Venus layer records how each one says yes to closeness, set out in Libra and Sagittarius Venus placements for these signs. The small rhythms of home belong to the Moon, and Libra and Sagittarius Moon signs covers them.
If a birthday falls near a sign change, check it first. The guide to the 12 zodiac signs has the real Sun dates for each sign. The start of Libra moves between September 22 and 23. The start of Sagittarius moves between November 21 and 22.
How I measured this
You can redo each number on this page.
For the Sun sign shares, I used two daily birth files published by FiveThirtyEight. One comes from the Social Security Administration and covers 2000 to 2014. The other comes from the National Center for Health Statistics and covers 1994 to 2003. I found each Sun sign change with astronomy-engine, an open source sky library, in the tropical zodiac. I spread each day’s births evenly over its 24 hours in Chicago time. When the Sun changed sign that day, I split the births by the hours before and after.
For the pair rate, I assumed partners’ birth dates are not linked, which is what Voas found. The chance of one Libra and one Sagittarius is then two times the Libra share times the Sagittarius share.
For the sextile, I took the Sun’s position at each hour of the birth years, weighted by births. I built the spread of Libra Sun degrees and Sagittarius Sun degrees. Then I combined them to get the spread of the gap. Both birth files gave the same shares to a tenth of a point. As a check, a simple formula that treats degrees as flat gives 19, 36, 46 and 56 percent, within half a point of the table.
For the 60 days, I timed the Sun from each degree of Libra to the same degree of Sagittarius, for every year from 1990 to 2030. I did it once with astronomy-engine and once with the short solar formula of Jean Meeus. Both gave the same days to within a hundredth.
For Venus, I read the Sun and Venus every six hours from 1600 to 2400, then again every hour. Both runs agree within a tenth of a point. The Jupiter share is the one our site has measured over whole laps of Jupiter.
For the old rules, I read Ptolemy’s Book 1, chapters 5 and 13 to 19, in the Robbins version. I checked Lilly’s names for the two planets in Christian Astrology.
Frequently asked questions
Are Libra and Sagittarius compatible?
Astrology reads the pair as an easy one. The signs sit 60 degrees apart, and Ptolemy calls that angle harmonious. Both signs are ruled by a benefic, Venus for Libra and Jupiter for Sagittarius. No study has shown that any sign pair lasts longer, so treat it as a lens, not a forecast.
How common is a Libra and Sagittarius couple?
In US birth data, about 1 random pair in 74 is one Libra and one Sagittarius. That is close to plain chance. Libra ranks fifth of twelve in US births, and Sagittarius is one of the three rarest signs.
Is every Libra and Sagittarius pair a sextile?
By sign, yes. By degree, no. With a 6 degree orb, only about 36 percent of pairs have Suns in a real sextile. The rest range from about 30 to 90 degrees apart.
Are Libra and Sagittarius the only signs ruled by both benefics?
No. Taurus and Pisces are also ruled by Venus and Jupiter and also sit a sextile apart. Libra and Sagittarius are the only such pair made of masculine signs, air and fire.
Can a Sagittarius have Venus in Libra?
Yes. About 9.3 percent of people with the Sun in Sagittarius have Venus in Libra, over the years 1600 to 2400. In the same way, about 9.4 percent of Libras have Venus in Sagittarius.
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