How we calculate your kundli
Most astrology sites are black boxes. We aren't. Every chart on ShubhLekha is computed by an open, test-pinned engine using the same astronomy that powers observatories — and classical Parashari rules applied faithfully. Here is exactly how.
🔭 Observatory-grade ephemeris
Planetary positions come from the MIT-licensed astronomy-engine, agreeing with reference ephemerides to within an arc-second. No lookup tables, no rounded almanacs — the real sky at your birth instant.
🌗 Topocentric Moon
We compute the Moon from your exact birth place, not Earth's centre. Parallax shifts the Moon up to ~1° — enough to change a nakshatra or pada at a boundary. We get it right.
📐 True Lahiri ayanamsa (and more)
Sidereal positions use the Chitrapaksha (Lahiri) ayanamsa, anchored to the Swiss-Ephemeris value with the full precession curve and nutation. Prefer another school? Choose True Chitra, Raman, or KP — your astrologer's call.
🕉️ Faithful classical methods
Whole-sign and Porphyry houses, Vimshottari mahā→antar→pratyantar dashas, KP sub-lords, Ashtakavarga, Shadbala, graha drishti, and divisional charts D1–D60 — all by the book (Brihat Parashara Hora Shastra).
✅ Pinned against real charts
Our output is cross-verified against published references and regression-pinned by an automated test suite. One example: a popular API reports a Sarvashtakavarga total of 342 where the classical maximum is 337 — ours is the correct 337.
⚖️ Honest about strength models
Shadbala (six-fold strength) is shown as a relative ranking in rupas — excellent for "which planet is strongest", which we surface freely. A few sub-components (Ayana, the Hora-lord Kāla bala, and exact Cheṣṭā) are simplified, so we label it indicative rather than quoting absolute virupa values we haven't fully derived.
🕰️ Honest about time & place
We resolve your birth instant with the historically-correct timezone (including pre-1947 India and DST for diaspora births), or Local Mean Time for very old records — never a hardcoded offset. A wrong offset alone can move your ascendant by a whole sign.
What this means for you
A kundli is only as honest as the maths behind it. We'd rather show our work than ask you to take it on faith. If you ever want to verify a position against Swiss Ephemeris or a trusted panchang, it will match — that's the whole point.