In short: Reading two charts together won’t give you a compatibility score, and it can’t tell you whether a relationship will last. What it shows is how the other person works, especially where they work differently from you. Human Design shows how your energies meet, astrology shows what each of you needs to feel safe and how each shows affection, Ba Zi shows how your elements feed or press on each other, and numerology shows the road each of you is on. It works for partners, parents and grown-up children, friends and business partners, as long as both people take part.
“Are we compatible?” It is the first thing people ask when they hear I read two charts together, and I always give the same answer: that is the wrong question, and I can’t answer it. Charts that look effortless on paper can belong to people who can’t share a kitchen, and charts full of friction can belong to couples who have been happy for forty years.
What two charts can tell you is far more useful. They show you how the other person works, in the places where they work differently from you.
Why isn’t it a compatibility score?
Because people aren’t recipes. Two charts can share very little and still make a warm, lasting partnership, because the two people are kind, curious and willing to adjust. Two charts can fit beautifully and still struggle, because of timing, history or choices that no chart decides.
A score would also do harm. Tell a couple they score badly and every argument afterwards becomes proof. Tell them they score brilliantly and they stop paying attention. Neither helps anyone.
What does help is understanding. Friction in a chart usually points to the place where you’ll learn the most from each other. Ease points to what comes naturally and can be taken for granted. Both are worth knowing.
We assume other people run on our fuel
Most misunderstandings between people who love each other come from one quiet assumption: that the other person is built like us. If I recover by being alone, your wish to talk it through tonight feels like pressure. If I decide in a second, your need to sleep on it feels like doubt. Neither is true. We’re simply made differently, and nobody ever showed us the other one’s manual.
Think of the small, daily things. One of you likes plans made a week ahead, the other hates being pinned down. One goes to bed tired and wakes up full of ideas, the other is useless before coffee. One shows love by fixing the car, the other by asking how your day really was. None of it is wrong. All of it causes friction when you don’t know it is built in.
What does each system show about the two of you?
Human Design shows how your energies meet. Put together someone with a steady motor and someone who works in short bursts, and one will always be ready to go while the other needs to lie down. Knowing each other’s type ends a surprising number of arguments about who is lazy and who never stops. It also shows where one of you takes on the other’s moods and amplifies them.
When I put two bodygraphs side by side, I look at the places where you complete each other, where one of you has one half of a channel and the other has the other half. Those connections create a strong pull, and sometimes a strong push. I also look at the centres one of you has defined and the other has open. The open person feels that energy more strongly in the other’s company, which can be lovely, and can also be tiring if nobody knows it is happening.
Astrology shows what each of you needs to feel safe and how each of you shows affection, which are often two different languages. One brings practical help, the other wanted words. Both were saying “I love you”.
The Moon describes what you need to feel at home and looked after. Venus describes how you give and receive affection, and what you find beautiful. Mars shows how you act, push and get angry. Comparing the two charts, planet by planet, is what astrologers call synastry, and it is often where the “aha” comes.
Ba Zi shows how your two elements relate. One person’s Day Master may feed the other’s, steady it, or press on it. This says a lot about who naturally gives and who receives, and why one of you sometimes feels drained without knowing why.
The five elements move in two cycles. In the nourishing cycle, Wood feeds Fire, Fire makes Earth, Earth bears Metal, Metal carries Water and Water nourishes Wood. In the controlling cycle, Wood breaks up Earth, Earth contains Water, Water puts out Fire, Fire melts Metal and Metal cuts Wood. Control isn’t bad: a river needs its banks. It simply helps to know which way the current runs between you. Ba Zi also shows the years when the two of you are carried by the same current, and the years when you’re each busy with your own.
Numerology shows the road each of you is on. A builder and a free spirit can make a wonderful pair, as long as each stops trying to convert the other. It also shows your personal years side by side, which explains a lot when one of you is bursting with new plans and the other wants to clear out the attic.
What it looked like at home
The first reading of this kind I did was for one of my daughters and me. We’re close, and we share a great deal of daily life. I thought I knew everything there was to know about us.
I didn’t. Seeing our two charts side by side showed me why some of my well-meant encouragement landed as pressure, and why her way of starting things looks nothing like mine. We ended up with a handful of small agreements: who does what, when to ask and when to leave alone, how to tell each other we’ve had enough for the day. Nothing dramatic. Living side by side became noticeably lighter.
Not only for couples
I call it the Duo reading because it is for any two people: partners, a parent and a grown-up child, sisters, old friends, two people going into business together. The one condition is that both take part. I don’t read someone who hasn’t agreed to it.
It suits long relationships that have settled into patterns, and new ones too: a couple who have just married or moved in together, or two people who barely know each other yet and are about to work side by side. In a new relationship, it saves years of guessing. In an old one, it often explains arguments you’ve been having on repeat since the beginning.
How to use what two charts show
Read for understanding, not for blame. “Your chart says you’re stubborn” helps nobody. “So that’s why you need a night to decide” helps a lot.
Turn insights into small agreements. Who plans the holidays, how much notice the other needs, what to say when one of you is running on empty.
Watch the timing. When your cycles pull in different directions, give each other room rather than taking it personally.
Go back to it. The pages are worth rereading after a hard week. They tend to make more sense the second time.
Frequently asked questions
Can astrology tell if a relationship will last?
No, and I don’t try. What the charts show is how two people work, where they meet easily and where they rub. Whether a relationship lasts depends on the two people and the choices they make.
What is synastry in astrology?
Synastry is the comparison of two birth charts, planet by planet, to see how they interact. It looks especially at the Moon, Venus and Mars, and at the links between the two charts. It describes the dynamic, not the outcome.
Can you do a compatibility reading for a parent and child?
Yes, as long as both are adults and both agree to take part. It is often one of the most helpful pairings, because parents and grown-up children have so many habits built in from years ago.
Do both people need their birth times?
It helps for the astrology houses and the Ba Zi hour pillar. Without an exact time, most of the picture can still be read, and I’ve written about what the birth time changes.
Can I give a Duo reading as a present?
Yes, and it makes a lovely one for an anniversary or a wedding. I’ve written about giving a reading as a gift, including how the voucher works.
Would you like to see your two charts side by side?
Each of you has your own personal reading first, because I need to know each person properly before I can read you together. Then comes the Duo reading: a written document for the two of you and a call with both. If you’ve both already had a personal reading with me, the Duo starts from €240.
About Catherine
I’m Catherine Polet. I’ve read Western astrology, numerology and Ba Zi for many years, and Human Design completed the set. I’ve also taught yoga and autogenic training for more than thirty years, and I’m a holistic nutrition health coach. I write every reading myself, one person at a time, in English, French, Spanish or German, from my home in Southwest France. Read my story.
