The short answer

Two who want a bigger world, and neither wants to own it. By the rule of elements, Sagittarius is fire and Aquarius is air — and the rule approves this pair. Keep that in mind and read on, because the rule answers far less than it seems to.

Fire with air, and it is one of the easiest pairs in the series. Both defend freedom on principle, both take an interest in whatever nobody else is discussing, and neither makes a scene about jealousy. Aquarius gives Sagittarius a cause and Sagittarius gives Aquarius a body — pulling them out of theory and onto the road. It is a pair that tends to be, before anything else, a very good friendship.

What the element rule says, and what I measured

The table every magazine publishes is simple: fire matches fire and air, earth matches earth and water. It was not invented yesterday, and it has a geometric reason — signs of the same element sit 120 degrees apart, and allied elements sit 60 degrees apart. Those are the trine and the sextile, the two aspects that tradition calls harmonious. The compatibility table is the aspect table applied to a single planet.

It puts half the zodiac on each person's list, which already shows how little information that is. And it can be tested against the numbers. I drew a random sample of 600,000 pairs of birth dates between 1966 and 2025, using the same ephemeris that builds charts on this site, and asked: in the pairs the rule approves, do the other pieces follow along?

The columns are the same. Knowing that the rule approves or fails your pair tells you nothing about the other person's Moon, nothing about desire, and nothing about how many contacts the two charts have. And 50.0% is exactly what a coin toss would give you.

That does not make the table false. It makes it small: it describes a trait of temperament, read from a single point on the chart. Using it to decide who to date is reading a book by its title's first letter.

Sagittarius and Aquarius in practice: where this pair gets stuck

The blind spot is the bond. Both are so good at giving space that nobody asks for closeness, and the relationship can go cold without either of them noticing in time — there is no fight, there is distance. And there is a friction of rigidity: Aquarius is fixed and defends its position; Sagittarius is mutable and changes its mind mid-conversation just for the fun of it. To Aquarius, that isn't lightness, it's lack of conviction.

What holds this pair together is the Moon, and it's Venus, because those are the pieces of affection that neither Sun sign brings on its own. A water Moon in either of them changes the whole house: someone shows up who asks how the other is doing and waits for the answer.

What usually unblocks things: scheduling time together. Two people who never demand each other's presence need to arrange presence, because it doesn't happen on its own — one dinner a week put on the calendar solves what no amount of good will solves. And Sagittarius gains by not switching sides for fun in the conversations Aquarius takes seriously: to them, consistency isn't stubbornness, it's character. And Aquarius gains by saying they missed the other, even thinking the sentence unnecessary: Sagittarius doesn't read the lack of demands as fine — they don't even notice the absence happened. And it's worth naming what this pair has: a friendship that turned into a relationship still needs both things, and when the friendship part takes up all the room, both are slow to notice the other part is gone.

What the element table doesn't look at in this pair

The element rule reads one thing only: the element. Each sign carries two other labels the table ignores, and in both cases they say more about the day-to-day than the element does. The modality — cardinal, fixed or mutable — is the way a person goes into a subject: cardinal starts it, fixed holds it, mutable changes it. And the ruler is the planet that gives the sign its vocabulary.

Sagittarius is mutable and ruled by Jupiter; Aquarius is fixed and ruled by Saturn.

Mutable with fixed, in its lightest version, because the fixed sign here is air and doesn't fight over territory — it fights over ideas. Aquarius sets down a principle and Sagittarius agrees with the principle and does whatever they want anyway, which works until someone notices. And nobody tends to notice quickly, because neither one is keeping watch.

Jupiter and Saturn, the two great social planets, here in the combination with the least friction: Jupiter expands and Saturn, in Aquarius, organises instead of braking. Both want to change something in the world, and the division sorts itself out — one brings the enthusiasm and the reach, the other brings the structure and the consistency.

And there is the similarity that guarantees it will last: neither of them is possessive. This pair can handle distance, travel, seasons spent in different cities — and it's one of the few pairs where that isn't a symptom of anything.

The one thing your sun sign decides about the other person

There is one exception to "the table tells you nothing", and it comes down to pure geometry. Venus never moves more than 47.2 degrees from the Sun — it is an inner planet, and from Earth's point of view it stays tied to the Sun's light. Given your sun sign, your Venus can only fall in five signs.

So the distance between two sun signs decides the odds that both Venuses land in the same sign. Measured across the same 600,000 pairs:

Sagittarius and Aquarius sit 60° apart — a sextile — which puts this pair in the 12.9% bracket. The two of you may well have Venus in the same sign, and it is the one affinity your sun sign guarantees, at least a little.

Notice what the table does with the element rule: it cannot follows the rule. Pairs the rule fails come out on top of the list, and pairs it approves come out at the bottom. The Venus link is real, and it is geometric — and it is why the compatibility table sometimes seems to work. It works a little, and not for the reason it claims to.

What no sign table can reach

Four pieces that change everything, and that no sun-sign table can reach:

• Each person's Moon. It is the way you feel, need and settle down — the piece that most decides day-to-day life together. It changes sign every two and a half days.
• The Ascendant. It changes every two hours and depends on the city. Two Sagittarians born on the same day can arrive at a party in opposite ways.
• The house each one falls into on the other's chart. The same Venus in your house 5 and your house 12 is passion in one case and a private matter in the other. This layer needs both people's birth time.
• What each one has already lived. Age, past relationships and the timing of the meeting weigh more than any aspect — and none of it is in anyone's chart.

This crossing is what's called synastry, and it needs both people's date, time and city of birth. Comparing sun signs is what's left when you don't have that.

And the limit stated out loud still holds: astrology decides nothing for anyone, doesn't tell you to stay or leave, and doesn't replace conversation or therapy. It gives you vocabulary. A couple who discover that one Moon needs routine and the other needs novelty have gained a better question than they had before.

Frequently asked questions about Sagittarius and Aquarius