How we calculate
What we calculate, which assumptions we use, and where the limits of accuracy are.
Most calculations on the site run in your browser with JavaScript. Your birth date, time or city are not sent to a server. The main assumptions are below.
Time and place
Indian cities use Indian Standard Time (IST, UTC+5:30). Panchang defaults to sunrise in New Delhi; changing the city in a tool changes sunrise, sunset and Rahu Kaal.
Ayanamsa and planets
Planet positions come from standard astronomical formulas. Lahiri (Chitrapaksha) ayanamsa is subtracted to get sidereal signs. The Moon uses a truncated Meeus series. This is adequate for a general panchang but not as precise as a professional ephemeris.
Kundli
The ascendant uses local sidereal time and latitude-longitude to find the rising sign. Houses are shown in the whole-sign method. Dasha follows the traditional 120-year Vimshottari system.
Limits of accuracy
- A wrong birth time can change the ascendant and nakshatra.
- Sunrise can differ by a few minutes with local horizon and elevation.
- Muhurat dates are only a first filter of tithi, nakshatra and weekday; the full lagna and local panchang are still needed.
- Astrological meanings come from tradition, not scientific proof.
If you spot an error, write to hello@nakshatrachat.club with the date, time and city.
Explore the tools
Kundli, gun milan, nakshatra and moon sign — all free and without signup.