Calculator
Sidereal sign calculator
Enter your birth date, time and place to see every planet in both zodiacs, side by side: your Western (tropical) signs and your Vedic (sidereal) signs, your rising sign in each, and your atmakaraka. Signs that change are marked in red.
Why most of your signs move back one
The sidereal zodiac starts about 24° later than the tropical one (the gap is called the ayanamsa). A planet in the first 24° or so of a tropical sign falls in the previous sidereal sign. A planet in the last 6° or so stays put. The full story is in why your sign is different in Vedic astrology.
How this calculator works
It runs Twenty-Seven’s own chart engine. Tropical positions are where the planets are against the equinox; sidereal positions subtract the Lahiri ayanamsa for your birth moment. The rising sign needs your birth time and place. Rahu and Ketu use the mean nodes, as most Vedic astrologers do. The engine is tested against Swiss Ephemeris.
Without a birth time the calculator uses noon and leaves the rising sign out. If a planet changed sign during your birth day (usually only the Moon), you’ll see both.
Questions people ask
What is my sidereal sign?
Your sidereal sign is where a planet sits in the star-based zodiac used by Vedic astrology. It is usually one sign earlier than your Western (tropical) sign.
Why is my rising sign different in Vedic astrology?
The ascendant shifts by the same ayanamsa as the planets, about 24° today, so it often lands one sign earlier.
What is the atmakaraka?
The planet at the highest degree within its sign in your sidereal chart, from the Sun to Saturn. Jaimini astrology calls it the soul’s significator. More here.
Is my data saved?
No. Nothing you enter here is stored.
See your full Vedic chart
In the app, Twenty-Seven computes your whole sidereal chart, starts with your Moon’s mansion, and talks you through it. It is an AI astrologer, and it remembers your life as you tell it.
Twenty-Seven is an AI astrologer, not a person. It makes no predictions: in its view the planets are clocks, not controllers.