Why is my Vedic sign different? Sidereal vs tropical calculator
Your Vedic sign is usually the sign before your Western one because Vedic astrology uses the sidereal zodiac, fixed to the stars, and Western astrology uses the tropical zodiac, fixed to the seasons. The gap is the ayanamsa, about 24 degrees today.
Two zodiacs, two reference points
The tropical zodiac starts at the March equinox, so it follows the seasons. The sidereal zodiac starts from a point fixed against the stars. Because Earth's axis slowly wobbles (precession), the two have drifted apart by about 24 degrees over the centuries. That gap is the ayanamsa.
Vedic astrology uses the sidereal zodiac. This calculator uses the Lahiri ayanamsa, the standard in India, and shows the tropical sign next to it so you can compare.
Which one is right?
They answer different questions. Western astrology measures the Sun's position against the seasons, and Vedic astrology measures against the star background. Neither is a calculation mistake. Many people use both, or follow the tradition they grew up with.
When your sign stays the same
If a planet is in the last six degrees or so of its tropical sign, it stays in the same sign in the sidereal zodiac. A planet earlier in its tropical sign moves back one sign.
Frequently asked questions
Why is my Vedic sign different from my Western sign?
Vedic astrology uses the sidereal zodiac and Western astrology the tropical zodiac. They are about 24 degrees apart, so most signs shift back one sign.
What is the ayanamsa?
It is the angle between the two zodiacs. The Lahiri ayanamsa is about 23.85 degrees in the year 2000 and grows slowly each year.
Did my zodiac sign really change?
No. Your birth chart is the same. You are comparing two different ways of dividing the sky into twelve parts.
Which ayanamsa does this tool use?
The Lahiri ayanamsa, also called Chitrapaksha, the standard used in India.
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Vedic Astrolab is an AI companion, not a human astrologer. Astrology here is a lens for reflection, not a prediction. Results are calculated from the NASA JPL DE421 ephemeris with the Lahiri ayanamsa; see the how-it-works page for the method and its limits.