Zodiac Compatibility — Check Any Pair by Birthday
Pick two birthdays and see which pair you are. Below, how to read a match through its two axes: element and modality.
Check a pair by birthday
Pick the month and day for each person. Birth year and time do not change a sun sign.
Both move first and learn by colliding, so things pick up speed fast. The comfort here is not having to explain what you want. The trouble is that neither backs down — once a disagreement starts, small things escalate, and a contest over who is right rarely ends cleanly.
One opens new ground, the other holds it. Starting force meets staying force, and things actually run. Still, the fixed side is unsettled by frequent change and the cardinal side chafes at standing still — the pace has to be agreed on.
Read this pairingWhat sun sign compatibility actually shows
Sun sign compatibility maps the broad places two people meet and miss each other. It needs nothing but a birth date, which is why it is the fastest read available — and also why it cannot reach how each of you shows feeling (the Moon) or gives affection (Venus). Treat the result as an outline of how the two of you catch and how you slip, not a verdict.
Two axes draw that outline. Element (fire, earth, air, water) says how alike you are in taking the world in; modality (cardinal, fixed, mutable) says who starts things and who holds them. Matching elements with matching modalities can still collide, because neither of you gives ground — while a mismatched element with different modalities often runs smoothly, because the roles divide themselves.
Order changes nothing. Leo and Aries is the same pairing as Aries and Leo, and this site keeps it at a single address.
Three ways elements meet
The twelve signs group into fire, earth, air and water. For a pairing, what matters is less which element you are than what the two elements are to each other.
Same element
There is an ease that needs no explaining — you value the same things, so little gets misread. The catch is that the blind spots match too: whatever neither of you is good at simply never gets done.
Elements that feed each other (fire–air, earth–water)
One starts it, the other grows it. Air feeds fire and water softens earth: each of you is more yourself with the other in the room. This is the pairing that runs with the least friction.
Elements that need translating (fire–water, earth–air)
The tempos differ. One considers a thing settled that the other is still holding. Once each learns the other's way it runs deep, but left unlearned only one side keeps getting hurt.
Three ways modalities play out
Modality comes from the start, middle and end of a season. If element is what you value, modality is how you move inside a relationship.
Same modality
You move at the same speed, but the roles overlap. Two starters (cardinal), two holders (fixed) or two adapters (mutable) leave the same gap unfilled.
Cardinal with fixed
One opens things up, the other keeps them. The roles divide naturally — until the one starting gets impatient and the one holding refuses to move, and it locks.
Anything with mutable
Mutable is the side that adjusts. Conflict rarely escalates, which is exactly the risk: nobody thinks to ask what the accommodating one actually wanted.
Pairings published so far
These went out first. For any other pair, the calculator above still gives you the element and modality structure.
Browse by sign
Each sign page covers its own traits and the signs it tends to work with.
Frequently asked
Can a sun sign alone tell you the match?
It gets you the broad structure. How each of you shows feeling (Moon) and gives affection (Venus) needs a birth time and place to calculate, so a sun sign match is best read as the outline.
Does the order of the two signs change anything?
No. Aries and Leo is the same pairing as Leo and Aries, and the site keeps both at one address.
Is a mismatched element a dealbreaker?
No. Elements that clash simply take longer to translate. That translating is what makes each of you explain your own way of doing things — pairs that get through it are often steadier than same-element ones.
What about two people of the same sign?
Both the strengths and the blind spots double. Nothing is faster to understand, and nothing that both of you avoid ever gets done.
For the real thing — birth date, time and place, not just the sun — SOLUNA runs the chart for you.
See your chart in the app