Free Astrology Tool — Real Astronomical Calculation
What are your Sun, Moon & Rising signs?
Your astrological "Big Three" — calculated with genuine astronomical formulas from your exact birth date, time and location, not a generic lookup table.
Your Sun sign is the core of who you are — your identity, your ego, the "you" underneath everything else.
Your Rising sign (or Ascendant) is the mask you wear on first meeting — how the world sees you before anyone gets to know you.
Your Moon sign is your emotional inner world — how you feel, need and process things beneath the surface.
What this means together
Your Big Three, explained
Astrology isn't just one sign — it's a snapshot of the whole sky at the moment you were born. These three placements form the foundation of any birth chart.
Your core identity and ego — calculated from your birth date alone.
Your emotional inner world — calculated from your birth date and approximate time.
How you come across to others — calculated from your exact birth time and location.
Want the real sky above the place you were born?
Beyond your Big Three, a personalized Birth Chart star map recreates the exact stars visible at your birth date, time and location — a unique piece of your story, written in the sky.
Get my personalized star map — €17.99Common questions
Your Big Three are your Sun sign (core identity), Moon sign (emotional inner world) and Rising sign (how others first perceive you) — together they give a far fuller picture than your sun sign alone.
Your Sun sign only needs your birth date. Your Moon sign needs your birth date and approximate time, since the Moon changes sign roughly every two and a half days. Your Rising sign needs your exact birth time and location, since it changes roughly every two hours as the Earth rotates.
Yes — this calculator uses genuine astronomical formulas (Julian Day, sidereal time, ecliptic longitude) rather than generic sign lookup tables, the same methods used across professional astrology software.
You can still get your Sun and an approximate Moon sign. Your Rising sign specifically requires an exact birth time to calculate, since it shifts roughly every two hours.