Sagittarius and Aquarius compatibility gets high marks on most sites. Fire meets air, both signs love freedom, and the page moves on. We asked three plain questions instead. How many US couples are a Sagittarius and an Aquarius? Did real marriages favor them? And what do the old books say about these two signs as a pair?
The first answer is the one that sets this pair apart. It is about 1 random US couple in 79. That makes it the rarest pair of two different signs that does not include Capricorn. The second answer is no: in 9.5 million British marriages, the pair sat a quarter of a percent above chance. The third answer is a story about two slow planets, Jupiter and Saturn, and a sky that treats this pair as neighbors who can see each other.
This guide shows how we got each answer, so you can check it. Read it as a lens, not a forecast. Astrology is not a science, and no study has shown that a sign predicts how a couple will do.
The short answer, in seven lines
| Question | What we found. |
|---|---|
| How common is the pair in the US? | About 1 random couple in 79, or 1.26 percent. |
| What would an even split of signs give? | 1 couple in 72, or 1.39 percent. |
| Where does it rank? | 61st of 78 pairs, and the rarest mixed pair without Capricorn. |
| Did real marriages favor the pair? | No: a quarter of a percent over chance, well inside the noise. |
| How far apart are the signs? | Two signs, or 60 degrees, a link called a sextile. |
| Who rules the two signs? | Jupiter rules Sagittarius and Saturn rules Aquarius. |
| When did those two rulers last meet? | On December 21, 2020, in the first degree of Aquarius. |
Why this pair is rare in US births
Your Sun sign is the slice of the sky the Sun stood in when you were born. Each slice is 30 degrees wide. Sagittarius season runs from about November 22 to December 21. Aquarius season runs from about January 20 to February 18. The exact hour moves a little each year. Our zodiac signs guide checks each date against the real sky.
The twelve signs are not the same size in births. Two things set the count. The first is how long the Sun stays in the sign. The second is how many babies are born per day at that time of year.
Both signs lose on both counts. Earth is closest to the Sun in early January, so it moves fastest then. That makes the Sun cross the winter signs a little quicker. It also helps to know when babies are born. US births peak in late summer and dip in winter. The holidays push the count down more.
| Sign | Days the Sun stays, 2000 to 2014 | Births per day, against the yearly mean | Share of US births. |
|---|---|---|---|
| Sagittarius | 29.56 days | 1.7 percent below | 7.95 percent. |
| Capricorn | 29.44 days | 5.3 percent below | 7.63 percent. |
| Aquarius | 29.59 days | 2.1 percent below | 7.93 percent. |
| Leo, for contrast | 31.29 days | 4.6 percent above | 8.96 percent. |
Look at the gap in the middle. Capricorn sits between the two signs, and it is the rarest sign of all. It holds Christmas Day, when US births fall to 57 percent of a normal day. It holds New Year’s Day, at 68 percent. Hospitals plan fewer births on those days. Sagittarius gets Thanksgiving in most years. Aquarius gets the tail of the winter dip.
So a Sagittarius and an Aquarius are two people born on either side of the year’s low point. The two signs are close to twins in size. The Sun spends almost the same time in each, less than an hour apart on average. Each one holds just under 8 percent of US babies. The stays in the table cover 2000 to 2014, the years of the birth file. Over the site’s reference window, 1600 to 2400, they are 29.557 days for Sagittarius, 29.446 for Capricorn, 29.592 for Aquarius and 31.292 for Leo.
How we got 1 couple in 79
We used 62.2 million US births from 2000 to 2014, by exact date. The counts come from the Social Security Administration, as published by FiveThirtyEight. We gave each day to the sign the Sun was in, using the real hour the Sun changed sign. A day split by a sign change was split by the hour, on Central time.
A couple can be a Sagittarius woman with an Aquarius man, or the other way round. Both count. So the chance is two times the first share times the second. That is 2 times 7.95 percent times 7.93 percent. The answer is 1.26 percent, or 1 couple in 79.
We checked it a second way. The National Center for Health Statistics published US births from 1994 to 2003, 39.7 million of them. With those counts, the pair comes out at 1.25 percent. The rank does not move.
Where the pair lands among all 78
There are 78 possible sign pairs: 66 pairs of two different signs and 12 pairs of the same sign. We ranked all 78 by how common they are in US births.
| Rarest pairs of two different signs | Share of random US couples | One couple in. |
|---|---|---|
| Capricorn and Aquarius | 1.21 percent | About 83. |
| Sagittarius and Capricorn | 1.21 percent | About 82. |
| Capricorn and Pisces | 1.23 percent | About 81. |
| Aries and Capricorn | 1.24 percent | About 80. |
| Scorpio and Capricorn | 1.25 percent | About 80. |
| Sagittarius and Aquarius | 1.26 percent | About 79. |
The five pairs below this one all contain Capricorn. So this is the rarest mixed pair that leaves Capricorn out. In both sets of births it ranks 61st of 78. The most common pair, Leo and Virgo, shows up in about 1 couple in 62.
What does that mean for you? Not much in love, and it is worth saying so. A rank like this comes from the calendar and hospital schedules, not from the stars. It tells you how many of these couples you will meet. It says nothing about how the pair gets on.
What ten million marriages showed
A birth count tells you how common the pair is. It does not tell you if the pair works. For that, the best test we know is a British one.
In 2007, the sociologist David Voas, then at the University of Manchester, looked at the married couples in the 2001 census of England and Wales. That was 10.3 million couples, with the birth date of both partners. He asked a plain thing. Do some sign pairs marry more than chance would predict? Do others marry less?
His answer was no. The one clear excess was couples of the same sign. He traced it to form errors, such as one birthday typed in for both partners. Once he took those out, the table matched chance. His paper is titled “Ten million marriages: a test of astrological love signs.” The Skeptical Inquirer ran a version of it in March 2008.
We pulled the Sagittarius and Aquarius cells from his cleaned table, Table 7. That table holds 9.5 million couples. The expected count is what you would get if people chose partners with no regard to sign.
| Couples in the 2001 census, cleaned | Found | Expected by chance | Gap. |
|---|---|---|---|
| Sagittarius wife, Aquarius husband | 60,545 couples | 60,629 couples | 84 couples under. |
| Aquarius wife, Sagittarius husband | 61,057 couples | 60,690 couples | 367 couples over. |
| Both ways together | 121,602 couples | 121,319 couples | 0.23 percent over. |
Is that small surplus a sign of fate? Here is the scale. For a cell of about 60,000 couples, chance alone moves the count by about 250 either way in a normal draw. One cell is below the mark and one is above it. Together they sit inside the noise. Among the 66 mixed pairs, this one ranks 19th by its surplus, near the middle.
The honest reading is simple. Sagittarians and Aquarians marry each other at the rate the calendar sets, no more and no less.
A sextile: two signs apart
Count from Sagittarius to Aquarius and you pass only Capricorn. That makes two signs, or 60 degrees. Astrologers call this link a sextile, from the Latin word for six. Six sextiles close a ring around the circle.
Ptolemy, the Greek writer of the second century, set out the rules in his book, the Tetrabiblos. In Book 1, chapter 13, he names four links: opposition, trine, square and sextile. He calls the trine and the sextile harmonious. His reason is that both signs in such a link are of the same kind. Sagittarius and Aquarius are both what he calls masculine signs. In the modern words, one is fire and one is air. Fire needs air to burn, and many writers lean on that image.
Is every Sagittarius and Aquarius couple a true sextile?
No, and the gap is large. A sign link counts whole signs. A true aspect counts degrees. Take a Sagittarius born on November 23 and an Aquarius born on February 17. Their Suns are almost 90 degrees apart, which is a square, not a sextile.
Astrologers allow some slack around the exact angle. That slack is called the orb. We ran the numbers for every pair of signs two apart, on the full range of birth dates. Only about 19 percent of such couples fall within 3 degrees of a true 60. The share is 36 percent within 6 degrees, 46 percent within 8 and 56 percent within 10.
So the sextile in the sign table is a rough label. If you want the real angle, you need both birth dates and a chart.
Two signs that see each other
Ptolemy adds a second kind of link, in chapter 15. He calls some signs “beholding.” These are signs where the Sun makes days of the same length. Here the two readings of his text differ, and we give you both.
The first reading works in degrees. It pairs each degree with the one that mirrors it across the winter solstice. William Lilly, the English astrologer of 1647, used this form. In it, Sagittarius mirrors Capricorn, so our pair does not qualify.
The second reading works in whole signs. Frank Robbins, who put the Tetrabiblos into English in 1940, lists the pairs in his note 83. Aquarius and Sagittarius are on his list. The two signs sit one on each side of Capricorn, the sign of the shortest days. Sun days in late November and in late January are close in length. In this reading, the pair sees each other across the dark of the year.
Ptolemy is clear on one more point, in chapter 16. Signs one or five apart are “disjoined,” with no link at all. Our pair is two apart, so it is not in that group.
Jupiter and Saturn: the rulers of this pair
Each sign has a ruling planet, its host in the old scheme. Jupiter rules Sagittarius. Saturn rules Aquarius. Modern writers add Uranus as a second ruler for Aquarius. The old books know only Saturn, since Uranus was found in 1781.
Ptolemy, in chapter 17, explains why. Saturn is the coldest and most distant planet. It gets the two winter signs across from the Sun and Moon: Capricorn and Aquarius. Jupiter sits just below Saturn and is milder. It gets the two signs next to those: Sagittarius and Pisces. So on the wheel, Jupiter’s sign and Saturn’s sign stand side by side around the midwinter point.
Both rulers belong to the day team
The old astrologers split the planets into two teams. The day team is led by the Sun and holds Jupiter and Saturn. The night team is led by the Moon and holds Venus and Mars. Each planet also has a day home and a night home. In Lilly’s words, Sagittarius is Jupiter’s day house and Aquarius is Saturn’s day house.
So this pair is made of the day homes of the two day planets. Ptolemy even links them. In chapter 18 he gives Saturn the lead of the air signs by day. He says the team of Jupiter “has familiarity with Saturn” because both are of the day.
A tradition is not a finding. Still, it gives a couple a useful picture. Jupiter in the old books means growth, faith and wide horizons. Saturn means limits, time and the long haul. One says yes to the road. The other asks what the road costs. Liz Greene wrote a whole book on Saturn and its slow lessons. Read this as a map of a talk you two could keep having, not a rule.
When the two rulers meet in the sky
Jupiter takes about 12 years to go round the zodiac. Saturn takes about 29.5. So Jupiter catches up with Saturn about once every 20 years. Astrologers call that meeting a great conjunction. Kepler wrote about the one of 1603.
We found every meeting from 1600 to 2400. The method was plain. We tracked the gap between the two planets every two days and closed in on each crossing by halving the time step. That gives 51 crossings. Some years hold three, as the planets back up in the sky. Grouping those gives 41 meetings, spaced 19.87 years apart on average.
| Sign of the meeting, 1600 to 2400 | Years it happened. |
|---|---|
| Sagittarius, the home of Jupiter | 1603, 1663, 1723, 1782, 2338 and 2398. |
| Aquarius, the home of Saturn | 2020, 2080, 2140 and 2199. |
So ten of the 41 meetings land in one of this pair’s signs. The one in living memory came on December 21, 2020, at about 18:21 UTC. In New York that was 1:21 p.m. The two planets met at 0 degrees 29 minutes of Aquarius, just after both had left Capricorn. We checked it against JPL Horizons, the NASA ephemeris service. The two routes agree to within five minutes.
The one of 1603 fell at 8 degrees of Sagittarius. The next meeting in Aquarius comes in March 2080.
Are your rulers at home?
A ruler is strongest in its own sign. That is rare for these two. Jupiter spends about a year in each sign, and Saturn about two and a half. So your ruler’s sign depends on your birth year, not your birthday.
Our sign pages measured this over a long window. Only 10.22 percent of Sagittarians have Jupiter in Sagittarius. Only 9.87 percent of Aquarians have Saturn in Aquarius. For a random Sagittarius and Aquarius couple, the chance that both rulers are at home is about 1 percent. The chance that neither is at home is about 81 percent.
So most couples of this pair do not have a “pure” Jupiter or Saturn. Where those planets sit in your two charts says more than the Sun sign does. See the Sagittarius sign page and the Aquarius sign page for the full tables.
What the tradition says the pair is like
With the numbers set aside, here is the picture the old and new writers paint. Take it as a lens.
- Sagittarius is a fire sign that changes shape, the last of autumn. Writers link it to travel, belief and the big question of why.
- Aquarius is a fixed air sign, set in the heart of winter. Writers link it to groups, ideas and the long view.
- Fire and air share a masculine, outward style in Ptolemy’s scheme. Both reach out rather than in.
- The friction point is pace. A shifting sign moves on. A fixed sign holds its ground once it has a view.
Stephen Arroyo, in his book on the four elements, ties air to thought and fire to drive. Neither one is an earth or water sign. So a fair question for this couple is who tends the body, the money and the feelings. Any couple can ask it, whatever the signs.
A good test is the Moon. The Sun shows the self you show. The Moon shows how you rest and what you need. Our page on Sagittarius and Aquarius Moon signs covers that second layer.
How this pair compares to its neighbors
Several sister pages use the same data, so you can compare. Our guide to Leo and Sagittarius compatibility covers the Sun and Jupiter as the lords of fire. Our page on Libra and Aquarius compatibility looks at an air trine. Our page on Taurus and Aquarius compatibility counts the couples whose rulers meet.
Saturn’s own clock matters to both of you. It comes back to its birth place near age 29, then again near 58. Our guide to the Saturn return gives the exact dates.
Questions people ask
Are Sagittarius and Aquarius a good match?
Astrology calls them a sextile, a link it counts as easy. No data backs that up. In 9.5 million British marriages, the pair married at the rate chance predicts.
How common is a Sagittarius and Aquarius couple in the US?
About 1 random couple in 79, or 1.26 percent. That is based on 62.2 million US births from 2000 to 2014. It is the rarest pair of two different signs that does not include Capricorn.
Why are Sagittarius and Aquarius birthdays less common?
The Sun moves through the winter signs a little faster, since Earth is closest to the Sun in January. US births are lower in winter too. Each sign holds just under 8 percent of US babies.
What planets rule Sagittarius and Aquarius?
Jupiter rules Sagittarius. Saturn is the old ruler of Aquarius, and modern writers add Uranus. Jupiter and Saturn both belong to the day team in the old scheme.
When did Jupiter and Saturn last meet?
On December 21, 2020, at about 18:21 UTC, at 0 degrees 29 minutes of Aquarius. They meet about every 20 years. The next meeting in Aquarius comes in 2080.
Is every Sagittarius and Aquarius couple a true sextile?
No. Only about 36 percent of such couples have Suns within 6 degrees of a true 60-degree angle. The rest are sextiles by sign only.
Go deeper with your personal Astrovision report
A sign pair is a starting point. Your own chart holds the Moon, Venus, Jupiter and Saturn too, each in its own place. A personal Astrovision report reads all of them for you, as a written guide and a podcast made for you.