Korean astrology · 사주
The chart you were born with.
Koju reads your Saju — the four pillars of your birth year, month, day, and hour — and turns it into daily guidance that actually feels like you.
Coming soon to the App Store · Free chart at launch
Today
A day for quiet momentum
Water feeds your Wood day master this morning. Start slow, hold your questions — the afternoon favors the bold ask you've been sitting on.
Today's energy
RisingYour four pillars
View chartHow it works
One moment in, a lifetime of readings out
No sign-up quiz, no twenty questions about your personality. Saju needs exactly one thing: when you arrived.
Tell us your moment
Your birth date, time, and place. That exact moment is the whole input — no quizzes, no personality tests.
Meet your pillars
Koju calculates your four pillars — year, month, day, and hour — and explains your five-element balance in plain language.
Live by the day
Every morning, a short reading on how the day's energy meets your chart. Two minutes, then get on with your life.
Inside the app
Three readings, one chart
01 · Your chart
Four pillars, five elements, zero jargon
Your chart is built from the traditional stems and branches of the East Asian calendar — then explained like a good friend would, not a textbook. See your day master, your element balance, and what they say about how you move through the world.
- Precise pillar calculation from your birth moment
- Element balance, explained in plain language
- The traditional Hanja, kept — because it's beautiful
Your chart
Wood day master
Element balance
Strong Wood tempered by Metal — you grow fast, and you prune well. Fire in your hour pillar wants an audience by evening.
02 · Daily readings
A reading for the day ahead
Each day carries its own pillar. Koju reads it against yours and tells you what to lean into and what to let pass — specific, short, and done before your coffee is.
- Written for your chart, not your sun sign
- Best hours of the day, mapped to your elements
- Two minutes, then get on with your life
Daily reading · 火 Fire day
Say less in the morning meeting.
A Fire hour clashes with your Day pillar before noon. Let others fill the silence — what you hold back today becomes leverage tomorrow.
Today's energy
Best hours
15:00 – 19:00Metal hours steady your Wood. Save the negotiation for the afternoon.
03 · Compatibility
Charts are better together
Partners, friends, co-founders. Compare charts to see how your elements feed — or fight — each other, and what to do about it.
- Element dynamics between any two charts
- Scores for communication, trust, and pace
- Share a reading with the person it's about
Compatibility
You & Mina
Wood feeds Fire
You bring the fuel, they bring the spark. Watch the burn rate in stressful months.
92
Talk
84
Trust
71
Pace
Your chart
Wood day master
Element balance
Strong Wood tempered by Metal — you grow fast, and you prune well. Fire in your hour pillar wants an audience by evening.
Try it now
Cast your pillars
Pick your birth moment and watch your chart assemble — the same four pillars the app reads every morning. No signup, nothing stored.
Cast your pillars · 사주팔자
Fire day masterBorn on a Fire yin day — the candle flame — focused, perceptive, quietly intense. Year of the Pig. The app refines this with your birth place and true solar time.
“Saju has guided decisions on the Korean peninsula for centuries — read at births, before weddings, at every new year. Koju is that tradition, read carefully, in your pocket.”
Questions
Fair questions, honest answers
What is Saju?
Saju (사주, “four pillars”) is Korean astrology. It reads the year, month, day, and hour of your birth as four pillars, each carrying one of five elements — wood, fire, earth, metal, and water. The balance between them describes your temperament, your tendencies, and how any given day interacts with them.
How is it different from Western astrology?
Western astrology is built around the positions of planets against star signs. Saju is built on the traditional East Asian calendar and the five-element cycle. It's less “what's your sign” and more a structured reading of one precise moment — which is why your birth time matters so much.
Do I need my exact birth time?
The more precise, the better — your hour pillar comes directly from it. If you only know the approximate time, Koju still builds the other three pillars accurately and tells you which parts of the reading depend on the hour.
Is Koju free?
Your full chart and a daily reading are free. A premium subscription unlocks deeper AI-assisted readings, unlimited compatibility charts, and more.
When can I get it?
Koju is coming soon to the App Store. Email us and we'll let you know the moment it's live.
Meet your chart
Koju is coming soon to the App Store. Be the first to read the moment you were born with.