How We Calculate Your Chart

The calculation system we use

Your chart is built using the sidereal zodiac with the Lahiri (Chitrapaksha) ayanamsa, the standard reference used across Vedic astrology. Unlike Western (tropical) astrology, the sidereal zodiac is anchored to the actual observed positions of the constellations in the sky.

Planetary positions are computed from established astronomical ephemeris data — the same class of precise positional data used in astronomy — rather than approximations or look-up tables.

How accuracy is ensured

• Precise coordinates: Your birth place is geocoded to exact latitude and longitude.
• Time handling: Your birth time and date are converted carefully to avoid timezone or date-boundary errors.
• Divisional charts: Vargas like the Navamsa (D9) and Dasamsa (D10) are derived mathematically from your base chart positions.
• Dashas: Vimshottari Dasha periods are calculated from your Moon's exact Nakshatra position.

What happens if you don't know your birth time

Birth time mainly affects your Ascendant (Lagna) and the house placements of your planets. If you don't know your exact time, we default to noon so that planetary signs and the Moon's position remain meaningful. In that case, treat house-based and Ascendant-based interpretations as approximate — the sign-level and Dasha insights still hold.

An honest note

Astrology is interpretive, not deterministic. We are precise about the astronomy, and humble about the meaning. Chetna is built for awareness and reflection — see our approach and disclaimer.