Leo Moon and Sagittarius Moon compatibility joins two fire signs in a trine, the easy angle of 120 degrees. Leo belongs to the Sun. Sagittarius belongs to Jupiter, the planet of growth and good fortune. On paper, it is one of the warmest Moon pairs in the zodiac.
It also hides an old rule of rank. In the notes of the translator Frank Robbins, Ptolemy’s signs that command and obey are listed by whole sign. On that list, Leo commands Sagittarius. This page explains what that means, what we measured in the sky, and how to use it without taking it too far.
The short version
| Question | Answer. |
|---|---|
| What angle do the signs form? | A trine, four signs or 120 degrees apart. |
| Elements and modes? | Both fire, one fixed and one mutable. |
| Who rules each sign? | The Sun rules Leo, Jupiter rules Sagittarius. |
| Rank of each Moon? | No rank in either sign. |
| Any special bond in Ptolemy? | Leo commands Sagittarius, but only when counted by whole sign. |
| How common is the couple? | About 1 couple in 72, like any mixed pair. |
A word of honesty first
Astrology is not a science. No study has shown that Moon signs predict how a couple will do. The biggest test of love signs came from the sociologist David Voas in 2007. He used the 2001 census of England and Wales, with 10.3 million married couples. He found no effect of Sun signs on who marries whom.
A census has no birth times, so no one can run that test on Moon signs. Read this page as a guide to old ideas and real sky facts. It can start a good talk. It cannot grade your couple.
A trine built into the rulers
Ptolemy wrote the Tetrabiblos in Alexandria around 150 AD. In Book 1, chapter 17, he gives each planet its signs. The Sun takes Leo and the Moon takes Cancer, the signs of high summer. The other planets take their signs in order, moving out from those two.
Jupiter gets Sagittarius and Pisces. Ptolemy points out that these two signs stand in trine to the homes of the Sun and Moon. Sagittarius is a trine from Leo. Pisces is a trine from Cancer. For him, that fit Jupiter well, since the trine is the most gentle link and Jupiter is the kindly planet.
So in this couple, the Sun’s sign and one of Jupiter’s signs meet in the very angle Ptolemy used to explain Jupiter’s rule. The Leo Moon takes its cue from the Sun: it needs warmth, pride and a place to shine. The Sagittarius Moon takes its cue from Jupiter: it needs room, meaning and a next horizon.
Two Moons with no rank
The old books rate the Moon in each sign. The Moon rules Cancer, is exalted in Taurus, and is weak in Capricorn and Scorpio. Leo and Sagittarius are on none of those lists.
William Lilly, in Christian Astrology in 1647, called a planet with no rank in its sign peregrine. The word means a traveler far from home. A peregrine Moon is not weak. It leans on the planet that owns its sign.
Our guide to the Moon in Leo says this Moon needs a witness more than a crowd. Our guide to the Moon in Sagittarius looks at why so many of its birth dates are split between two signs. Here, both Moons stand on equal footing. Neither is at home, and neither is in trouble.
Fire with fire
Ptolemy, in chapter 13, calls the trine a friendly link, because both signs are of the same kind. Here, both are fire. Fire is warm, quick and open. A fire Moon wants life to feel big.
The two Moons share that hunger. They like to laugh, plan and make things happen. The Leo Moon brings heart and loyalty. The Sagittarius Moon brings humor and a sense of adventure. Stephen Arroyo, who wrote about the four elements, saw fire as the element of faith and enthusiasm. Two fire Moons have plenty of both.
Fixed meets mutable
The mode of a sign says how it moves. Leo is fixed, which means it holds on once it has chosen. Sagittarius is mutable, which means it adapts and moves on. Among the 78 Moon pairs, this is the only fire trine that joins a fixed sign to a mutable one.
That is where the work lies. The Leo Moon wants a home base and a steady bond. The Sagittarius Moon wants freedom and a long leash. The Leo Moon can feel left behind when the Sagittarius Moon wanders. The Sagittarius Moon can feel tied down when the Leo Moon wants a promise.
Leo commands Sagittarius, by whole sign
In chapters 14 and 15, Ptolemy adds two more bonds between signs. Some signs command and others obey. Some signs see each other as equals. Modern readers count these bonds in two ways, and the lists do not match.
The reading by whole signs
Robbins, in note 80 of his translation, lists the pairs that command and obey by whole sign. Aries is the pivot. Signs at the same count on each side of it form a pair: Taurus and Pisces, Gemini and Aquarius, Cancer and Capricorn, Leo and Sagittarius, Virgo and Scorpio. The sign in the summer half commands, since it brings the longer days.
On that reading, Leo commands and Sagittarius obeys. In a couple, the Leo Moon sets the mood and the Sagittarius Moon goes along with it. That is a bond of rank, not of love. It says who leads, not who cares more.
The reading by degree
Other astrologers read the same chapter by exact degree. They mirror each point across the start of Aries. William Lilly called these mirror points contra-antiscia. On that reading, the list shifts by one sign. Leo commands Scorpio, and Sagittarius obeys Cancer. So by degree, Leo and Sagittarius have no special bond.
This pair is not disjunct, or cut off, on either reading. Ptolemy gave that name to signs one or five apart. By whole signs, 24 pairs are disjunct. By degree, 16 are. Four signs apart, this couple is in neither group.
What we measured: a perfect balance of phases
Every Moon sign spends close to the same time in the sky, between 8.33 and 8.34 percent. So no Moon pair is rare. Any mixed pair comes out at about 1 couple in 72. A pair of the same sign is 1 couple in 144.
One real gap does show up by sign. It is about the phase of the Moon at birth. A person born near a new moon has the Moon in the same sign as the Sun. A person born near a full moon has the Moon in the sign opposite the Sun.
| Moon sign | New moon type, Sun in the same sign | Full moon type, Sun in the opposite sign. |
|---|---|---|
| Leo Moon | 8.43 percent, with a Leo Sun | 7.96 percent, with an Aquarius Sun. |
| Sagittarius Moon | 7.96 percent, with a Sagittarius Sun | 8.44 percent, with a Gemini Sun. |
The two rows are almost mirror images. The Earth is farthest from the Sun in early July, so the Sun moves slowest in the northern summer. It lingers in Leo, which gives more new moons there. It lingers in Gemini too, which gives more full moons in Sagittarius. In late autumn and winter, the Sun speeds up. It rushes through Sagittarius and Aquarius, so fewer Leo Moons are full moons and fewer Sagittarius Moons are new moons.
For the couple, the two leans cancel out. 15.72 percent include at least one partner born near a new moon. 15.73 percent include at least one born near a full moon. The gap is too small to matter. What matters is the mirror between the two signs, and it held on both routes we used.
In the old reading, a Leo Moon with a Leo Sun speaks with one voice. A Sagittarius Moon with a Gemini Sun has a mind that asks questions and a heart that wants answers. Our guide to moon phase compatibility shows how to find your own phase.
How close are the two Moons in degrees?
An angle by sign is not always exact in degrees. Astrologers allow a margin around the exact angle, called an orb. The Moon moves at a near even pace through each sign, so plain geometry gives the share of couples inside each orb.
| Orb allowed | Couples with a true 120 degree angle. |
|---|---|
| Within 3 degrees | 19 percent of couples. |
| Within 6 degrees | 36 percent of couples. |
| Within 8 degrees | 46 percent of couples. |
| Within 10 degrees | 56 percent of couples. |
These shares are the same for every Moon pair. They come from geometry, not from Leo or Sagittarius. One edge case is special to this pair. A late Leo Moon and an early Sagittarius Moon can sit close to 90 degrees apart. That is a real square hidden inside a trine by sign. At an 8 degree orb, it happens in 3.56 percent of couples.
Check both Moons before you read
A reading needs two correct Moon signs. The Moon stays in a sign for 54.6 hours on average, from 46.9 to 61.1 hours. It changes sign on 43.92 percent of all days. A birth on such a day has two possible Moons.
Tools with no birth time use noon. That guess gives the wrong Moon sign in 10.98 percent of charts. For a couple, it gives the wrong pair in about 1 case in 5, or 20.75 percent. Only 31 percent of couples have both Moons fixed by the date alone. Our main page on Moon sign compatibility gives the full count.
For this pair, a late Leo Moon can turn out to be an early Virgo Moon. An early Sagittarius Moon can turn out to be a late Scorpio Moon. Either change breaks the fire trine. The birth time settles it.
Sun, Moon and Venus: three different pairs
The same two signs mean different things for each planet. Our page on Leo and Sagittarius Sun sign compatibility looks at the core self. Our page on Venus in Leo and Venus in Sagittarius looks at how each partner loves and flirts.
The Moon pair is about comfort. It shows what each of you needs after a hard day. A couple can share a Moon pair and have very different Suns. Read all three before you draw any line.
Three talks worth having
- How much freedom is enough? The Sagittarius Moon needs space to roam. The Leo Moon needs to know it comes first. Say where the lines are, and keep them.
- Who leads? By one old rule, the Leo Moon sets the tone. Check that the Sagittarius Moon agrees, and swap roles on purpose.
- Is it a joke or a jab? The Sagittarius Moon speaks bluntly and laughs it off. The Leo Moon takes pride to heart. Ask before you tease.
For another fire trine with a Leo Moon, see Aries Moon and Leo Moon compatibility. For the third fire trine, see Aries Moon and Sagittarius Moon compatibility.
How we measured
We used two separate routes over the years 1600 to 2400, with every moment weighted the same. Route one used the astronomy-engine library. It found each sign change of the Moon and the Sun to within a tenth of a second, then added up the exact time in each case. Route two used the Swiss Ephemeris and checked the sky once an hour, on a grid shifted by half an hour. The two routes agree to within 0.05 points.
The noon test uses calendar days in Greenwich time, with a chart at 12:00. For the old rules, we read the Tetrabiblos, Book 1, chapters 13 to 17, in the Robbins translation, with his notes 80 and 83, and Lilly’s Christian Astrology.
Frequently asked questions
Are a Leo Moon and a Sagittarius Moon compatible?
Astrology reads them as a friendly fire trine. Both Moons like warmth, fun and big plans. No study has shown that Moon signs predict how a couple does, so use the reading as a lens, not a verdict.
Does Leo command Sagittarius?
Yes, when you count by whole sign, as in note 80 of the Robbins translation. Counted by exact degree, the pairs shift, and Leo commands Scorpio instead.
Is the Moon weak in Leo or in Sagittarius?
No. The Moon has no rank in either sign, which tradition calls peregrine. It leans on the ruler of the sign, the Sun for Leo and Jupiter for Sagittarius.
What is the main friction in this pair?
Pace and freedom. Leo is a fixed sign that wants a steady base. Sagittarius is a mutable sign that wants room to move. Talk about it early.
Can I find my Moon sign from my birth date?
On 56 percent of days, yes, since the Moon stays in one sign all day. On the other days, you need a birth time. A noon guess is wrong in about 1 chart in 9.
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