When people ask “how accurate is Vedic astrology?” they usually mean two different things: how precise is the calculation, and how reliable is the interpretation. They deserve separate answers.
Calculation precision is objective
The position of every planet at any moment is an astronomical fact. High-quality astrology software uses the Swiss Ephemeris — the same data professional astronomers rely on — to compute positions to a fraction of a degree. At this level there is no ambiguity; a planet is where it is.
The ayanamsa decides your signs
Because Vedic astrology is sidereal, the ayanamsa (the offset from the tropical zodiac) determines which sign and nakshatra a planet falls in. Using the wrong ayanamsa — or none — can shift a planet across a sign boundary and change the entire reading. The Lahiri ayanamsa is the accepted standard.
Method discipline separates good from bad
- Strength measured with classical Shadbala rather than guesswork.
- Yogas and doshas detected by deterministic Parashara rules — same chart in, same result out.
- Timing from the Vimshottari dasha system, not vague “soon”.
- Honest confidence: weak signals shown as weak, not inflated.
Where uncertainty really lives
The genuine uncertainty is in interpretation and free will — how a tendency expresses depends on choices and context. A responsible reading gives probabilities and windows, not guarantees. Be sceptical of anyone promising certainty about the future.
A practical test
Ask any astrology service how they calculate: which ephemeris, which ayanamsa, which house system. If they can’t answer, the precision question is already answered. Sivayan publishes its full methodology for exactly this reason.