Your real zodiac sign, calculated with astronomical precision
Calculate Your Free Sidereal Birth ChartExplore all 12 real zodiac signs with their actual astronomical dates
→Learn the 12 astrological houses and their meanings in sidereal astrology
→Ayanamsa, Nakshatras, Dashas, Lunar Nodes and more sidereal concepts
→Guides and resources about sidereal astrology
→Sidereal astrology is the system of astrology that aligns the zodiac with the actual, observable positions of the constellations in the sky. Unlike tropical astrology, which is based on the seasons and the position of the Sun at the spring equinox, sidereal astrology tracks the real movement of the planets against the backdrop of the fixed stars.
This means that your sidereal sun sign is likely different from what you have always been told. Due to the precession of the equinoxes — a gradual shift of about 1 degree every 72 years — the tropical zodiac has drifted approximately 24 degrees from the actual constellations. The result: most people discover they are one sign earlier than they thought.
Our calculator uses the Swiss Ephemeris, the same astronomical engine trusted by NASA and professional astronomers, together with the Lahiri Ayanamsa — the international standard for sidereal calculations. This ensures that every planetary position in your birth chart reflects where the planets actually were at the moment of your birth.