What synastry is
Synastry compares two birth charts. One person's chart is laid over the other's to see which planets are linked by aspects: where there is attraction, where understanding, and where friction is bound to come.
Unlike star-sign compatibility, synastry looks not only at the Sun but also at the Moon, Venus, Mars, Mercury and the rising sign. That is why two Aries–Libra couples can turn out completely different.
How to make a synastry chart
- Enter your date of birth, the time if you know it, and start typing your town — pick it from the list.
- Press «Next: your partner» and enter your partner's birth the same way.
- Press «Build the synastry»: the table draws one wheel — your planets outside, your partner's inside, and lines for the links between you.
- Under the table: the couple's harmony, your Suns and Moons with their tarot cards and the strongest links. The full reading can be ordered right there.
The elements of your Suns and Moons
The first thing a synastry looks at is the elements of the Suns and Moons. Fire, earth, air and water live and feel in different ways: fire and air feed each other, so do earth and water, while fire with water or earth makes a union of bright contrasts.
The Suns speak of character — what drives each of you. The Moons speak of feelings: how each of you loves, worries and finds calm.
Fire and fire
Two fire Suns: both quick, bright and eager to act. Together it is easy to catch fire over a shared idea and never be bored — and just as easy to flare up at each other. Agree on who leads in what, and rivalry turns into shared excitement.
Both Moons are fire: you both cool down quickly and love strong emotions. Together it is fun and fiery, but in an argument neither wants to give in first.
Fire and earth
Fire and earth: one catches fire and hurries, the other weighs things up and builds to last. The fire partner brings courage and new beginnings, the earth partner steadiness and getting things done. Friction comes from pace: one feels it is all too slow, the other that it is all too risky.
The fire Moon looks for excitement and reacts at once; the earth Moon looks for peace and a reliable routine. One needs support for their impulses, the other the certainty that tomorrow everything will be in its place.
Fire and air
Fire and air is one of the easiest combinations: air fans the flame. You find each other interesting, one picks up the other's ideas, and the couple is full of movement, talk and laughter. Just make sure plans and conversations do not crowd out depth and getting things done.
The fire and air Moons easily lift each other's spirits: you are happy together on the move, travelling and talking. You both tend to put heavy feelings aside — remember to talk about those too.
Fire and water
Fire and water: passion meets sensitivity. The fire partner is direct and cools down fast after a quarrel; the water partner feels deeply and remembers hurts for long. The attraction is strong, but fire should be gentler with words, and water should say what it feels instead of waiting to be understood.
The fire Moon pours feelings out at once; the water Moon lives them deeply and for long. Fire should take care not to hurt with sharpness, water not to store up grievances but to speak about them.
Earth and earth
Two earth Suns: both value reliability, clear plans and real results. Such a union stands firmly on its feet — a shared home, money and goals come easily. The one risk is routine: bring new experiences into the relationship, or calm turns into boredom.
Both Moons are earth: comfort, order and practical care bring you both calm. Emotionally you are very reliable for each other — just do not forget to show tenderness in words too.
Earth and air
Earth and air: practicality meets ideas. The air partner brings lightness, new people and an outside view; the earth partner knows how to turn ideas into deeds. Friction comes when one lacks freedom and the other certainty; clear agreements help.
The earth Moon needs stability and deeds, the air Moon conversation and freedom. Show each other what care means to you: one waits for actions, the other for a talk.
Earth and water
Earth and water is a natural, warm combination: water nourishes the earth. The earth partner gives support and practical care, the water partner tenderness and understanding without words. Together it is easy to make a home — just do not shut yourselves away from the world.
The earth and water Moons complement each other beautifully: one gives support, the other warmth and understanding. With such a partner you feel calm and safe.
Air and air
Two air Suns: you understand each other at half a word and love talk, ideas and people around you. The couple has plenty of freedom and lightness. The weak spot is everyday life and commitment: talk them through, since words are your strength.
Both Moons are air: you live your feelings through conversation. It is easy for you to discuss anything — just do not let talking about feelings replace the feelings themselves.
Air and water
Air and water: mind meets feeling. The air partner explains and reasons, the water partner feels and waits for a response from the heart. You can teach each other a lot — as long as feelings are not dismissed with logic and reasoning is not taken as coldness.
The air Moon makes sense of feelings with words, the water Moon senses them deeply and silently. The water partner needs more warmth and patience, the air partner more freedom and clarity.
Water and water
Two water Suns: a deep emotional bond, understanding without words and strong attachment. You sense each other's moods better than anyone. Protect the union from hurts that pile up in silence and from shared anxiety: say your feelings out loud.
Both Moons are water: you feel each other without words and grow strongly attached. Protect each other from swings of mood — between you they are contagious.
Aspects between the charts
Aspects are the angles between the planets of the two charts. Trines and sextiles are harmonious links: here things come easily. Squares and oppositions are tense: here is friction, but also growth. A conjunction is a fusion — two planets side by side whose themes intertwine.
The links between the Sun and the Moon, Venus and Mars, and the Moon and Venus matter most: they speak of attraction and of how at ease you are together.
The full synastry reading
The full synastry reading goes through every important link between your charts: attraction and romance, emotional understanding, talk and everyday life, shared values and the lessons of the relationship — and ends with advice for the two of you.
Questions and answers
Can I make a synastry chart without the time of birth?
Yes. Without the time there are no rising signs or houses, and the Moon may have moved into the next sign that day, but the links of the Sun, Venus, Mars and the other planets are still exact.
How is synastry different from star-sign compatibility?
A star sign is only the Sun. Synastry compares all the planets of two charts and the links between them, so it shows exactly where things come easily for you and where you will need to meet halfway.
What does the harmony percentage mean?
It is the share of harmonious links among the links between the personal planets and rising signs of the two charts; exact links weigh more. It is a guide, not a verdict: happy couples have tense aspects too.
Is it free?
Yes: the wheel, the couple's harmony, the Suns and Moons and the strongest links are free. Only the full synastry reading is paid.
Compatibility by the destiny matrix →
Solar return: the chart of your year →
The planets are calculated with Astronomy Engine; towns and time zones: GeoNames (CC BY 4.0).